Is this entitled behaviour from a 24 year old?

[donttellthem]

It was my relative's big birthday recently and she took the extended family out for a meal. Her daughter (an only child) was 24 the day after my relative's birthday and insisted on sharing the celebration. So the cake had 24 as well as the big number on it. They both blew out candles and we sang *happy birthday dear xxx and xxx".

Details vague so as not to be outing.

There are more examples where she behaves this way, but the birthday really did annoy me.

Am I alone in thinking that this is very entitled behaviour.

I cannot imagine a world where I would not celebrate my child's birthday at the same time as mine if our birthdays were so close together. I doubt the parent is jealous of her own child.