MIL told people we are pregnant when we asked her not do

So at 10 weeks we caved and told our parents only because I am wedding dress shopping and wanted my mom and MIL to be aware that a baby was on the way. We told them individually and asked them to keep it private because we wanted to wait until I’m out of the first trimester. This is my first baby after being diagnosed with infertility so I’m just very protective of it all because so much of this feels unknown and uncharted territory.

The weekend we went dress shopping, my MIL let it slip that she told everyone at her job already. I immediately told her that it was wrong, it’s not hers to share and I didn’t want people who don’t even know us to be aware of our pregnancy before our own loved one and friends are in on it. She said sorry and I dropped it because I didn’t want to be too aggressive or mean about it but I assumed firmness about it was enough for her to know she was wrong and messed up.

Then TODAY, I find out she also told my fiancé’s brother. I haven’t addressed it with her but honestly I’m not just angry, I feel betrayed. My MIL was like a girlfriend to me and the fact she just shared all of this with whoever she felt like without thinking of us and her relationship with me feels like a serious violation that I’m not gonna get over. Just looking for some community and seeing how others feel like I should address it. I don’t want to have a fight but I do want her to know she damaged our relationship, this is something I don’t care to come back from, and she’s never gonna be let in on something important to us ever again.