(this is an essay I wrote in response to someone who had written an essay claiming that, first, one could not meaningfully speculate about "cartoon characters" having sexual intercourse, and secondly that, if one could meaningfully speculate about this, Quinn was definitely sexually experienced).
"The Honor of the Quinn" by Jordan S. Bassior
Daria is a fictional reality. In order to ask logical questions about the "internal" state of any fictional reality (i.e., what is implicitly true about the reality based upon consistency with what has been explicitly shown), we must willingly suspend our disbelief and, temporarily, believe that the fictional reality is "really real."
This doesn't mean that we go insane and really believe that Daria, Quinn, Jane etc. are "real people" in the sense that we might run into them on the street someday. They are not really real, not in the sense that you or I are real. It means that we play "let's pretend", and pretend for the sake of argument that the fictional reality is real.
Now, this is true regardless of the mode of presentation of the story.
"Cartoon" is a "mode of presentation", not a "level of reality." The Morgendorffers are no "more fictional" than the Bunkers or the Bundys, despite the fact that the "mode of presentation" of Daria is "cartoon" and the "mode of presentation" of All in the Family and Married With Children is "live action."
"Degree of realism" is a seperate issue from "mode of presentation." Monty Python's Flying Circus is a (mostly) live action show, but its "degree of realism" is very low. By contrast, Macross is a cartoon (specifically, an "anime" styled cartoon), but its "degree of realism" is fairly high. One can assume that characters on Macross are capable of having sex; one can't be quite as sure that characters on Monty Python's Flying Circus are.
Daria has a fairly high degree of realism. Some slightly slapstick things happen, but for the most part they are mildly improbable rather than wildly impossible. The main improbability is the number of funny things that happen, but that's because the "type of fiction" that Daria falls into is "comedic drama." The level of realism is, in fact, roughly equivalent to (or higher than) Married with Children.
There is absolutely nothing in Daria that suggests that the characters live in an asexual universe. Characters fall in love, lust after each other, and make sexual advances. Yes, the camera cuts away from them before they actually do anything more explicit than kissing or very tamely caressing one another, but that's because the show is, in terms of "degree of sexual explicitness," what would normally be considered "PG" (there is some dirty language and sexual innuendo, but no actual presentation of nudity or explicit sexuality).
It is thus reasonable to assume that, in the "internal reality" of the show there is actual sex going on. What do you imagine O'Neill and Barch did after the camera cut away in "The Daria Hunter" or "Just Add Water", or Helen and Jake did in "Antisocial Climbers" or "Fire!"?
Now, you might argue, a character such as Kelly Bundy has a real physical body, so she can "have sex" in a manner which Quinn cannot. So the question "Is Kelly a virgin" has a meaning which "Is Quinn a virgin" does not. Right?
Wrong.
Kelly Bundy has no more "reality" than does Quinn Morgendorffer. Both are fictional characters, living in a fictional world. The body you see displayed is that of the lovely Christina Applegate, whose virginity or lack thereof has no real bearing on Kelly Bundy's. To confuse the two is the classic mistake of the "obsessed fan" who mistakes the actress for her character.
(In fact, Christina Applegate and Kelly Bundy have almost antithetical personalities: Christina is a an intelligent and classy woman, while Kelly is a mindless bimbo; it's almost certain that the answer to the question would have been respectively "yes" and "no" during any of the early episodes, in which both Christina and her character were in their mid-teens).
The only difference between Quinn and Kelly in regard to the "reality" of their bodies is that Quinn's body is portrayed via a series of animation cells, while Kelly's via the motions of Christina Applegate. The cells are not Quinn, and Christina is not Kelly; in both cases they are "really real" only within their fictional realities.
(Consider the following: Quinn may also be portrayed in text, as she is in the script that the actress reads from, or in a fanfic. These means of portrayal don't make her "less real", though in the case of the fanfic the "Quinn" you are seeing is "less canonical", which is another issue. The same things apply to Kelly, of course).
As for Quinn's age, I don't see what there is about her being 15 1/2 years old that makes the question inherently perverted or silly. It's relevant, of course ... if you asked me "Is Aunt Amy a virgin" I would answer "almost certainly not" (because she's in her 30's and the chances are very great that she's had a lover or lovers by that time); likewise if you asked me "Is Rachel Landon a virgin" I would answer "almost certainly yes" (because she's prepubescent and there's no reason to think she's being sexually abused).
Quinn being around 15 means that she's old enough that if she wants to have sex, and isn't particularly scrupulous about whom she has sex with, she almost certainly isn't a virgin; it's also young enough that if she is reasonably moral and hasn't had any great love in her life, she almost certainly is. One of the many poignant things about adolescence is that it's the period when most people first make decisions of this nature.
Personally, I think Quinn's a virgin. Why? Because she clearly has no real love (or even liking) for the guys she dates: she shows an aversion to physical contact of any sort coupled with a general immaturity; and she was raised by a couple with traditional sexual values (the same couple that raised Daria, who is notably prudish).
It's obvious from this that she probably wouldn't want to have sex with any of her dates. Was she pressured into it?
Maybe. But when we see Quinn with guys in the show, it's very obvious that she's the one in charge. Quinn manipulates men; she rarely lets herself be manipulated in return, not figuratively and (I suspect) not literally either. Does Quinn's behavior fit any sort of common pattern? Yes, she does. She's a classic "flirt" or "tease" ... she uses (what appears to be an implicit promise of) sex to induce guys to attempt to please her, then gracefully maneuvers out of actually delivering on this promise.
What she's doing is playing "the game of dating", in which the guy tries to get sexually as far with the girl as fast as possible while giving her as little time and money as he can get away with, and the girl tries to get as much out of the guy in terms of time and money while giving him as little sexually as she can get away with. And she's very aware that it's a game, but she is so obsessed with it that she doesn't even realize that a more mature approach to love or sexuality is possible.
(Note: by "a more mature approach" I do not mean "more sexually active." What I mean is an approach that relates her actions to her emotions and that of the person she's inolved with, and the long-term serious prospects of the relationship, rather than to a game being played for arbitrary social points).
Quinn is very good at this game precisely because she's NOT romantically or sexually interested in any of her "boyfriends." She doesn't love any of them, and she's not really turned on by physical contact as such (she might be seducible by someone who knew how to sexually excite her starting with kissing and mild foreplay, but chances are that she doesn't know anyone fitting this description, since her dates are selected on the basis of social status, not sensuality).
As a result, Quinn probably has no problem saying "no" when she deems it inadvisable to proceed further. Despite all her talk of romance, what she's doing is as cold-blooded and calculating as one of Helen's legal negotiations. Neither her heart nor any less mentionable regions are seriously involved in the issue.
My theory is further supported by Quinn's strict rule about not dating anyone more than once per n weeks (I forget the number she quoted). The whole point of such a rule is to prevent the guy from being able to advance the argument "We've been going steady for [t amount of time], if you really liked me you'd go further." Quinn's strategy lets her go on an endless number of "first dates," and at 15 not even someone who flirts as outrageously as she does is really expected to go farther than first base on a first date.
(Her strategy is not going to work forever: as she gets older she's going to have to choose between "playing the game" and her moral values. But that's another issue entirely)