Lilly Moscovitz is the best friend of Mia Thermopolis and the younger sister of Michael Moscovitz. Lilly is very clever, saying that she has a IQ of 170. She is very determinated. In the books, she has her own show, Lilly Tells It Like It Is and it becomes very hugely popular in Korea. When Mia dumps Michael, Lilly and Mia becomes estranged until the end of the 10th series, when she admits she was angry at Mia because she thought she stole J.P from her. They become friends again, after Mia and Michael get back together. In the movies, she is portrayed by Heather Matarazzo.
Lilly is a slightly overweight girl with an IQ of 170 (at last count). She has a "squished" visage (similar to that of a pug) and "glossy" brown curls, although later in the series she dyes her hair blonde. Mia says that she thinks Lilly is pretty, but "according to today's admittedly limited ideal of what attractive is, Lilly doesn't really pass muster." She is loud-voiced and outspoken, with an extensive vocabulary that Mia cannot always understand. She and Mia have been best friends since kindergarten, and Mia lists her as one of her heroes. Lilly's psychoanalyst parents, the Drs. Ruth and Morty Moscovitz, finance her public access television show Lilly Tells It Like It Is until Lilly baits Norman, a stalker who repeatedly asks for her to remove her shoes on camera. She finds a new producer in Tina Hakim Baba, who receives an allowance of fifty dollars per week.
She goes out with Boris Pelkowski, but dumps him in the fifth novel after meeting Jangbu, an attractive Tibetan sherpa; by the time she regrets the breakup, Boris has already moved on with Tina. Lilly calls Tina a "black-hearted, backstabbing witch". She also tells Mia that she never stopped loving Boris after he dropped a globe on his head while trying to win his ex-girlfriend back. Lilly later falls in love with John Paul "J.P." Reynolds-Abernathy IV and goes out with him for roughly six months until he breaks up with her, blaming the breakup on the way that Lilly treats people - particularly Mia. However, J.P. actually broke up with her because he was falling in love with Mia, which leads to an estrangement between the two girls.
Lilly goes on to create the website ihatemiathermopolis.com, dedicated to criticizing Mia to the point of general abuse. (This is interesting because Mia writes in an earlier book that there is an ihatelillymoscovitz.com, created by her stalker Norman, where there are message boards by and for all the people who hate Lilly. As Mia writes it, there is a surprisingly large amount.) By the end of the ninth installment of the series, they seem irrevocably estranged, but the reason for Lilly's coldness towards Mia is revealed in the last novel, Forever Princess, and they resume their friendship.
Lilly is a strong supporter of free speech in school and believes that women are more intelligent than men. For this reason, her IM name is WomynRule.
Despite not being traditionally attractive, Lilly has had four boyfriends: her true love Boris Pelkowski, Jangbu Pinasa, JP Reynolds-Abernathy and Kenny Showalter.
Lilly's relationship with Mia started since they were in kindergarten. They were best friends since then.Lilly always dominated Mia.But it was Mia who helped her when she broke up with Boris.Later,in book 9,when she broke up with J.P,Lilly accused Mia of being the reason they broke up. She started a site called ihatemiathermopolis.com. In the 10th book, she was more friendly towards Mia and later made up with her. It is revealed that part of the reason she was so angry at Mia was because it was clear to her that JP was using Mia, but Mia did not realize it. Also, Mia broke her brother's heart.
Mia states in the seventh book, Lilly is the person she loves seventh in the world, after her bodyguard Lars and above her second best friend Tina.
Michael Moscovitz Edit
Lilly is Michael's younger sister and they have a normal brother-sister relationship, annoying each other but staying loyal. When Michael and Mia breaks up in the end of the 8th book, Lilly takes her brother's side and becomes estranged from Mia. However, when Michael returns, he finds out about Lilly and Mia, and tells Lilly to be nice to her. When Lilly hears Mia and Tina talking about Mia losing her virginity to J.P, Lilly tells Michael to be at the prom at midnight. He doesn't know why, but he figures it out when he hears J.P and Mia breaking up at the prom. Lilly tells Mia that if she ever breaks Michael's heart again, she'll break her face, literally.
Tina Hakim Baba Edit
After Mia, Tina is one of Lilly's closest friends. Like Mia, Lilly thought Tina was a freak until they become friends. In the fifth book, while suffering regret and guilt for dumping Boris, Lilly says that Tina will never make Boris happy. However, this was probably out of jealousy and remorse.
When Boris becomes hot in the sixth book, Lilly immediately takes out her barettes and applies lip gloss in the hope of charming Boris into loving her again. When Lilly was crying about how she was unpopular, Mia tells her she has lots of friends, Shameeka Taylor, Ling Su Wong and Tina. Lilly cries harder at the sound of Tina's name, remembering that she "stole her man".
In the ninth book, Tina goes to Lilly's party and tries to get her to forgive Mia. Lilly laughs and tells her not to be such a "Mia". When Tina chooses Mia over Lilly, Lilly becomes cold towards her too. It is likely they became friends again after Mia and Lilly make up.