Totally illegal!

Ichigo • I have one daughter. I'm also pregnant with my second. Unmarried.
So, I was at my professional development thingy at the place that got me an internship at a daycare. And we were talking about how to look professional on FaceBook as employers look at FaceBook pages. And she said that she saw on the news earlier that a teacher at a school who had been working there for 8 years got fired because parents complained about a picture of her kissing her wife on Facebook. She had been married before she even got the job. Being as though it's completely freaking illegal to do that as they knew she was married to her, I'm failing to see why she was fired. Frankly o think she should sue the hell out of that school.... 
What do you think.