I think it would be fun to have a baby sibling. I'm almost 19, and my youngest brother is 10. When I told my brothers I was pregnant, he said "I'm going to be an uncle at 10?"

Like thats a horribly young age or something, I was like, well.. not my fault I am the oldest.
However, my BF is the baby in his family, and he is 23!! He has a few nephews, but none that he has ever really been around alot/more than a few times a year. Thats what makes me nervous about him and our son.. but I'm sure he will be good. He usually is pretty good with his nephews, and when we are around my baby cousins he will hold them and such. He's only changed one diaper his whole life though, and that was like 6-7 years ago..

it will be quite an experience.
Anyways, I am getting off subject. Good luck to your mom! It should be lots of fun!