Do I unfriend or not?

It depends. Is she the type to talk shit on social media? If so, I would block her from my posts for now and restrict my viewing of hers but I would leave access in case I started getting messages that she was talking smack.

Also, it should be noted that stirring the pot is how I get my cardio

I'd unfriend. You can also mute for 30 days if you don't want to see what she posts but she can see you. I'd be temped to want to know if anything happens to the school, but in the end, the most healthy thing to do is unfriend, be polite and move on.

This isn’t quite the same.   I worked for a church for 13 years. We had several people, one in particular, who lived in my neighborhood, volunteered as much time as I worked almost, plus we were friends.  I started working a different church job, and reduced to two days at that original job.   That proved too much, so I quit the original job.   She stopped talking to me completely, I friended me on social, and I was fine with that.  

fast forward 2 years, Covid strikes my family, my husband dies, and I end up in rehab learning how to walk again. I get a card from her, first line. “I’m probably the last person you want to hear from”. I waited until I knew she’d gotten up and around (that’s how well I knew her) and called her.   She apologized, tried to explain, I said no need, water under the bridge, and I meant it.  

several months later, she passed from Covid as well, but before she died she had told her daughter that she had found peace in knowing she mended her relationship with me.  

so, unfriend, and block…that will probably be very healing and healthy for you.  And if the friendship is supposed to continue, you will find your way back.

From your description, it sounds more like "work" friends, which tend to fall off after you (or they) leave a job. In that case, if I really felt strongly that I had been wronged, I would unfriend.

However, it sounds like you are going to take some action that may potentially impact her livelihood. In that case, I think I would allow some grace based on past friendliness and put on mute and revisit in 30-60 days.