[AIW] for not letting my mother-in-law stay in our guest room for 3 months

My mother-in-law (MIL) is 67 years old. She lives in Houston. She has been hinting for months that she wants to "spend more time with the grandkids." My wife and I have two kids, ages 4 and 7. We live in a 4-bed house in Allen.

Last month, my MIL announced — not asked, ANNOUNCED — that she would be coming to stay with us for 3 months over the summer. She said she already cleared it with my wife.

I found out about this plan when my MIL mentioned it casually on a FaceTime call. My wife looked guilty. She had not told me yet.

Here is why I said no:

1. Three months is not a visit. It is a residency. A week? Fine. Two weeks? Stretching it. Three months? That is a quarter of the year. She would effectively be living with us.

2. She is not easy to live with. Previous visits have involved her rearranging our kitchen, criticizing how we feed our kids, making passive-aggressive comments about my cooking, and telling my wife she "works too much" instead of staying home with the children.

3. Our guest room shares a wall with our bedroom. Having her on the other side of the wall for 3 months changes the dynamic of our home in a fundamental way.

4. Nobody asked ME. My wife and her mother decided this together without my input. This is my home too.

5. I work from home. She "pops in" to my home office during visits to chat. I have told her I am working. She pops in anyway. Three months of that is untenable.

My wife says I am being selfish and that "family helps family." She says her mom is lonely in Houston and this would be good for the kids. She says 3 months is "not that long."

I suggested a compromise: 3 weeks instead of 3 months, and she stays at the Residence Inn in Allen (I offered to pay). My wife and MIL both said the hotel suggestion was "insulting."

Am I wrong for setting this boundary?