My Little Pony: Friendship is Magic - AJ's life goal is to get pumped full of kids by some stallion

With how important family is to AJ, makes sense she'd want to continue it on and form one of her own.

It's one of the things I like about her. She seems to have everything figured out for her, wanting a simple, humble life taking care of all the important things in her life.

I kind of assumed that while Big Mac is the oldest, he's less interested in managing the farm than AJ, so she is the one that "owns" it.