My thoughts on the characters:
Lara Jean - She and her family remind me of the Alice books by Phyllis Reynolds Naylor. I loved them as a teen, and I'm glad that a new series is reminiscent of them. For example, Alice's mom passed away, just like Alice's. Also, Kitty really is hoping for her Dad to date and tries to bring him and a neighbor together - just like Alice. Chris is a wild best friend, like Alice's friend, Pamela. And Lara Jean is "not popular," even though she's friends with popular people, goes to parties, and has a popular boyfriend - just like Alice. Anyway, I liked Lara Jean and how she grew throughout the series.
Chris - Great entertainment. I like how she's interesting and complicated, and so different from Lara Jean - and Lara Jean doesn't judge her for it.
Peter - I'm not a big fan of Peter. I liked John Ambrose better, but I respect Lara Jean's choice. That being said, I do think that Peter is an excellent character, and good for Lara jean (in spite of his meddling mother and absent father.) I especially enjoy how well he and Kitty get along; it's adorable.
Kitty - My favorite character in the book. She needs her own series.
Margot - I admire her for going away to college, and as the oldest sibling in my family, I relate to her.
Daddy - He's hilarious and I love his relationship with his girls.
Truly the best part of this series is the relationships between the characters. Here's hoping for a "Lara jean Goes to College" series or a spin-off Kitty series!