Will I be the ahole

How old is your sister?

Unless your sister is a child, I see nothing wrong with the day being about your baby and celebrating your sister at night

My son was born on my brother's birthday and I plan to do the same.

She In her late 20s not a child

I'd say happy birthday and get her a gift if that's what you usually do but I think you're totally fine to make the day about your baby. There's no need to ignore your sister though - that would be being a bit of an asshole.

At a celebration being held for your child, it makes sense that that time is about your child. Sister can be celebrated too but at a different time. Your daughter shouldn’t have to share her day just because someone else has the same birthday. And your sister shouldn’t understand that a child deserves 3 hours of undivided attention for their own birthday. If not, your sister would be the AH for competing with a baby for attention lol

My son and my brother are a week apart, instead of 2 parties/gatherings and everyone travelling twice in less than a week, I did a joint pizza party for my brother and my son’s 1st birthday. We did family only though and have done for family birthdays for years so it wasn’t weird to us 🤷🏼‍♀️ just meant that my 40+ year old brother blew out a candle on a dinosaur cake 🤣 think he felt special having a joint party with his nephew though and there was no overshadowing on any sides but like I say, that was family only!

Seems unnecessarily hurtful to ignore your sister

I voted by accident 😩 You celebrate your daughter’s birthday however you want too.. if your sister doesn’t like it, tuff.. she’s old enough to understand..

I think your sister is (hopefully) mature enough to understand. As long as you still celebrate her in someway later that day

Message your sister saying happy birthday and give her a gift. No need to ignore her that’s just childish. If the celebration is just for your kid then yes no need to mention sisters birthday other than the initial happy birthday and handing a present over