What was she thinking? I believe she was thinking she wanted to get laid. Not condoning this kind of thing but do you seriously believe there is any difference between a man and a woman as far has their wanting to snag some young stuff? Trust me there is not.
Then she should have approached a male 18 years or older who wasn't a student at the school she taught at. There are literally millions of qualified candidates who would have been more than happy to tend to her needs and desires. I'm glad she's going to prison.