This happened at my kids' school, too. Almost exactly the same story - divorce and everything. This particular woman also stole $ from Jr Football and I think Jr Baseball, but I'm not sure about baseball. It was *very* public and everyone knew (small town). She paid the money back and was criminally prosecuted. B/c she made restitution, she did not serve jail time, but was on an electronic tether for awhile and on probation for a long while. She was never really accepted back into the community and in fact most people won't even look at her, much less speak to her. I couldn't do that though - I was always nice to her and her children when I ran into her in public. I admit, I did feel sorry for her b/c I know how desperate she was - but I was shocked and disappointed at the same time.
She happened to be some kind of bookkeeper or accountant and also lost her job b/c she used the company card to go on vacation (told you it was a small town - everyone knows everything). Ultimately, she moved away.
And now, like other posters mentioned, the PTA has much stricter rules in place for how money is handled.
Sadly, I think all these parent run organizations are going to have to put stricter policies in place, b/c you just never know.