Am I wrong?

I apologize if this is more of a rant than anything.

I returned back to work January 14th and that same week my MIL started watching my daughter 1-2 days a week. Sometime between the 16th and the 26th I noticed that the straps on her car seat had been moved up a slot. She had been close to needing them moved up but I hadn’t done so yet because she would settle down in the seat during a ride and her shoulders were just under the next slot. I asked my husband about the straps being moved, assuming that he did it and he said that he never touched the straps. So we agreed his mom must have done it on a day she was watching our daughter.

I mentioned that it was kind of frustrating that she would do that and not mention anything about it to us. I said that it would be nice if she would have been like “hey I noticed she’s grown enough her straps can be moved up, care if I do it?” And my husband got all offended that I would want her to ask. I just feel like when it comes to something that impacts the safety of my daughter, I should be consulted. There was a reason I hadn’t moved up the straps. At the very least she could have told me she did it when I picked her up, but she didn’t.

Am I completely in the wrong for being upset like my husband thinks I am? Should I mention something to her about just giving us a heads up next time? I don’t want to seem unappreciative of the fact that she cares for our daughter when we are at work.