Julius the baby of the world is good.
It's all about this little girl who can't stand her baby Julius & all the adults saying how great he is & how he doesn't do anything great & then another kid decides not to like him & Lily gets all mad & decides he is pretty great. It's cute.
and this one:
Darcy & Gran Don't like babies
The fact is a new baby means lots of changes an older sibling won't like & I felt like both books addressed that really well. After the baby came I also talked to my Ds & asked him what he didn't like about being a big brother & what he did like. I never tried to convince him to like the baby. I did often tell him the baby said things. So when baby would make noises I'd say stuff like "Hey, did you hear that? The baby said you are the coolest big brother ever & he can't wait until he can play with you because being a baby is soooo boring".
IDK - it seemed to work. He never once said he didn't actually like his brother. He was always sweet & all of that. I tried really hard to make it out as if being a baby was pretty boring & how lucky he was that he could run & build towers & play cards & all the baby could do was lay around & poop himself. LOL It seemed to convince him.