So jealous of my SIL. Vent/ long.

I dont know how to get over this jealousy crap. When i first met my sil i was pregnant with my first, three months later shes pregnant with her first 9 months later shes pregnant with her second now a year later shes pregnant with her third already talking about her forth. Me and my hubby have been struggling woth fertility issues for three years my son is almost four and we started trying for baby no 2 when he was almost two. We finally end up pregnant in Feb her and her husband were not happy and i dont know why. My pregnancy ended in a misscarage 10 days after we found out.:( But anyways shes always rubbing her pregnancy in my face and i just want to smack her. She knows about the struggles too. It hurts so bad all i want is another baby that i cant have and here she has 2 a third on the way already talking about her forth just so she dont lose her benefits from the state. Sigh. I dont know if what im feeling is natural or maybe im just crazy and need help. Thanks for letting vent and taking the time to read it. Also thanks for being a wonderful support system. Baby dust to all y'all lovely ladies.