Unfair!

Cristal
So I just found out my ex sister in law is pregnant with her 4th. She's not married and she's not with the father, which I won't judge her for because I had my 1st in that situation. However, I was financially stable enough to raise him. Her, on the other hand, has never had a job as long as I've known her and she's on a bunch of state and government aid. All the while I can't seem to get pregnant no matter how hard my husband and I try! Am I the only one that gets pissed off by people like this? Or am I just being unfair to her because I'm having trouble getting pregnant?