Perhaps the show's most reviled character, I was attempting to pinpoint some of her positive traits. 1/ Since the Griffin's do not appear to have a housekeeper, I get the impression that Linda does the majority of the cooking, cleaning, food shopping and laundry. Not a simple undertaking for someone with a full time job. 2/ She is outwardly cold towards her family, but if Sandi has 30 pairs of shoes in her closet, I venture to guess that Linda bought her 25 of them as presents. Same can be said fot the rest of her daughter's wardrobe. She probably hasn't said "I love you" to her daughter in years because of her impassive demeanor, so she makes up for it under the guise of "I want you to look good". 3/ Pressuring Sandi to be attractive and popular isn't the worst thing in the world.
At this point in her life, Sandi is neither miserable nor overly happy. She probably derives some satisfaction from her social position in the high school, but she is still quite cynical. A spinoff chronicling her senior year would have made for interesting viewing.