Jealousy

I am currently ttc my second child and it isn't going well. A girl I went to high school with is now pregnant with her 6th child from a 4th baby daddy. Of her 5 current children, she only has custody of 2 of them and she only recently got them back from CYS. I am having so much trouble wrapping my head around how someone like that can conceive so many children so easily and I am here struggling. Anyone deal with feelings like this?