AITA for telling a mother her son isn't welcome in my yoga studio's adult classes anymore?

My name is Rachael, 52 F, I own a small yoga studio in a college town in New Hampshire. We offer adult classes, prenatal, and a kids' class twice a week. One of the rules that's been in place since I opened — posted on the website and on the sign-in sheet — is that adult classes are adults only. Simple rule. It's a studio, not a gym, there's nowhere for a kid to go while a parent is on a mat. A few months ago a woman started coming to my 9am power flow with her son, who was maybe 8. First time I figured was a one-off. She brought him with his iPad and set him up on a folded blanket against the back wall. I spoke to her after class, explained the policy, offered her the schedule for our kids' class and a flyer from the community center's drop-in childcare down the street. She said her son was "on the spectrum and can't be left with strangers" and that she "really needed this hour." I told her I hear her but the class isn't a suitable space for him. She came back the next week. Same thing. iPad at full volume for three minutes before I had to go mute it. Then the class after that went sideways. The boy was bored, fair, and started running laps at the back of the studio. Then he knocked over the rack of blocks. Then he was crying and slapping the window. I stopped class and went over to the mom. She said "he just needs to move, please give him a minute." I said he can't stay in this class. She said "you can't do this he has needs." Another student at the back said something sharp, I don't remember what, but it got ugly. I told her she needed to leave and that going forward the 9am wasn't open to her if her son needed to be with her. I also for the record offered to comp her a month of our kids' class for him AND a pass to our prenatal (she'd mentioned she was trying again). She said that was "insulting" and left. She's been posting in the town Facebook group about how our studio isn't "inclusive" and "doesn't support special needs families." Two of my regulars have said they're canceling over it. I love kids, I raised three. But my adult class isn't the place for one. Am I the asshole?