Help with sleeves on baby cardigan

Hello guys!

I hope someone can help me out. I’m currently trying to knit my friends baby a cardigan but I am stuck on the sleeves. I am following a pattern which basically looks like I don’t need to increase any stitches on the smaller baby sizes ( so like 0-3 months 0-6months etc) but I would have to on the older sizes. Is this typical? I’ve never knitted anything like this before. I’ve tried to put a picture on here but it keeps crashing. Any help would be greatly appreciated.

Welcome to KnittingHelp!
Can you give us a link to the pattern or a pattern name?
Do the directions have a 0 for the size you’re making?
It certainly might be that there’s no shaping, especially for smaller sizes in a baby sweater.