AITA for letting my girlfriend put my daughter in time out?

I had my daughter (7) in high school. I went to boarding school and her mom wanted nothing to do with her so she lived with my parents while I finished high school and college, until she was 6.

My daughter was not an easy baby so after a month my parents ended up getting her a live in nanny. Her nanny is an older Hispanic woman and always spoke Spanish with my daughter.

When my daughter moved in with me, the nanny came to. They still spoke Spanish at home, which wasn’t a big deal until recently.

My girlfriend moved in with us a few weeks ago. She’s been trying to get to know my daughter but my daughter refuses to interact with her, going so far as to refuse to speak English at home.

I told my daughter that she was being rude and needs to speak English at home and with my girlfriend but she pretended not to understand me so I went to my girlfriend and told her that if my daughter speaks Spanish to/around her, she can put my daughter in time out for 10 minutes.

The nanny complained that my daughter was spending at least an hour in time out a day and I’ve noticed that she hasn’t been speaking at all around the house.

Then I got a call from my parents asking why my daughter is asking to come back. I told them what happened and now they’re threatening to take my daughter back.

AITA for letting my girlfriend put my daughter in time out?

Edit: apparently she had an “emergency” at my parents house so they’re going to be keeping her there for now.