These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Hollywood Homely: Jess believes she is ugly because she has an A cup (at fifteen) and her arse is too big. On the cover of each book, she looks fine.
Les Yay: In Girl, Fifteen, Charming But Insane, the hidden bathroom camera catches two female best friends making out or "snogging" in the bathroom. This causes Jess to (very briefly) consider her own friendship with Flora, long enough to differentiate it from a Romantic Two-Girl Friendship.
Unfortunate Implications: Jess, who is touted as a strong and intelligent female protagonist, spends most of her life angsting over boys and seems to define her worth through her appearance and her ability to find dates. It is anti-feminist and not a great message to give young girls.
The books are a Stealth Parody and they do focus on other issues than just boys- the subplot with Jess' dad actually being gay, for example.
Wangst: This book has too many "my life is over" moments to count.