Proud of Me by Sarah Hagger-Holt

Winner of the Little Rebels Award 2022
 
Becky and Josh are almost-twins, with two mums and the same anonymous donor dad. Josh can't wait until he's eighteen, the legal age when he can finally contact his donor, and he'll do anything to find out more - even if it involves lying.

Becky can't stop thinking about her new friend, Carli. Could her feelings for Carli be a sign of something more? Becky and Josh both want their parents to be proud of them...but right now, they're struggling to even accept themselves.