Like the milestone idea. Or Baby Aspiration
One could could be a motor skill. Rowling, standing up, crawling.
When strollers then... TWIN strollers.
Ability to wrap the baby up while doing other things... MULTITASKING
Baby Mat/cradle that is portable and can be put on any lot.
Just the ability to go somewhere with your baby really.
Babys with personality... Baby that screams all the time, baby that smiles a lot, quiet baby and easy to take care of.
CAS
Babys with genetics. Eyes. Hair (some have hair, some dont), more skin tones. I find the baby creepy looking. Thought the bebes from the sims2 were the cutest.
I read that knifty knitting will have baby clothes which is cool. Always wanted that. Definitly a step in the right direction.
But to be honest. Some differente looking Clothes and Accessoires should come with the Base Game too.