Frustrated...

So my 7 month old, my husband and I are staying with my MIL until February (yes, I know awful, it wasnt ideal but had to be done + we’re paying rent and taking care of ourselves ).

She’s been okay but doesn’t know the meaning of boundaries, she wants to know everything about anything my husband and I talk about.

My issue is:

On Tuesday my mom video chatted me to see our little one, ( my mom only speaks Spanish so her English is a little funny) so she talks to my daughter in “baby talk” and my little one loooves it. My MIL heard this and she’s like “oh my god WHO IS THAT?”. Ugh this pissed me off so bad. My huband talked to his mom and her reasoning for saying this was “oh she’s normally very serious, I didn’t know that was her, sorry.” Still I think it was VERY rude of her. She texted me an “apology” pretty much summarizing what she told my husband. I was still just really hurt by it because I know for a fact she thought she did nothing wrong, she apologized just because my husband talked to her. She’s been avoiding me when were alone together, but I say “hi” when I do see her, that’s it.

I’m still a little hurt by all this and I’m going to have to talk to her soon, but I just don’t know what I can say to her.