boyfriends baby momma

Sarah • 21yr old, in love with my handsome guy. He`s the father to my bonus little girl & our baby boy💙
We announced our pregnancy on Easter and told his family then too it was very fun and sweet. Everyone is super excited. But my boyfriend gets a message from his baby momma saying "how'd everyone take it that Sarah's pregnant". The thing is we haven't told her or talked to her about it. She's not on either one of our social media accounts so it was shocking she said something. I guess I'm just asking if you guys think she actually cares or was trying to get the point out there that she knew? Was she trying to be ugly or was it genuine...?? Just want some thoughts or any similar situations to mine.