AITA for not telling my mother in law where I was going why she was babysitting?

I 32f am dating my long term boyfriend Peter 34. We have a beautiful 2 year old girl named Hannah.

We both work full time and help with Hannah equally. The past few weeks Peter has been working longer hours so I’ve been a little overwhelmed with Hannah and the house work.

I usually work Mondays but our office decided to close for maintenance. My daughter usually goes to daycare but they’re closed this week. My mother in law asked if she could watch our daughter while we worked to spend some extra time with her.

Peter suggested that I still have his mom watch our daughter for the day and take the day to sleep in and go the salon or spa for some me time. So Peter went and dropped off our daughter this morning and I picked her up on my way home about an hour earlier.

When I got there his mom seemed irritated and I asked her if everything was okay and she went off on me about how if she knew I was gallivanting she wouldn’t have watched Hannah today. I explained Peter told me I should still go so I thought he had told her when he dropped off Hannah this morning. His mom let me know he didn’t mention that.

I apologized for the miscommunication and thought that would be it. But she called all of his aunts after I left and now they’re all messaging me about being a horrible mother who just drops off her daughter. In 2 years the only time she’s not with him or I is when we’re working.

Peter doesn’t think I did anything wrong but everyone else thinks I did. So AITA?