MIL and baby names

Needed to vent somewhere. My husband and I have been very adamant with everyone that we are not discussing baby names with anyone. We want it to be just between him and I. So what does my MIL do? Posts in her Christmas letter what she wants the baby to be named. Worst part is she used my dads name (one we were actually thinking about). Now I feel like I can’t use it because she will gloat forever that she named the baby.