My brother is having a child

I know I am supposed to be happy for my brother...I am but at the same time, i am not...I am jealous that he is having a child before me. I am older than him, he is not ready for a child. Why is it always the people who weren’t even trying for a child end up becoming parents? And my mom won’t shut about becoming a grandma, it’s really getting to me. And than she had to nerve to tell to wait a couple years to have a kid...because everybody is about to go all out for my brothers child’s baby shower. I am not going to wait just because she says so..I don’t get it wouldn’t she want two grandchildren that are close in age...year apart or a few months a part.