Arrgh! Mark! said:
Has anyone else had any experiences with this? Advice, or problems?
Experience, heh, you could say that.
I'm a teacher in Missouri. I don't know how law works in Australia but here teachers have "moral turpitude", which means that anything that gives the appearance of a problem is a problem. Districts cannot afford lawsuits even if nothing happened, so there is no real support there. I'm NEA (teacher's union) so I'm not scared about lawsuit cost, but being a small community any problems will reflect upon my career and that of my wife.
Furthermore, this is the fringe of the "Bible Belt", lots of Assembly of God, Pentecostal, and Baptist churches about. I don't know about Australia, or even other parts of America, but there is still some faintly remembered stigma about D&D here. I have a kid in class who wants to play with his older cousin and his mother won't let him. I've also had one or more anti-Harry Potter parents nearly every year.
When I started my last campaign, I recruited some older high school boys to the game. I spoke with their parents. It went swimmingly well. One boy brought another, it seemed OK. Then that boy's mother, disturbed about her son playing with "older men" in a "hidden room" (an old poker room made out of a converted garage bay) called my principal. He was very apologetic, but said if there was any further issue there was nothing he could do and my job was in jeopardy. I posted this incident to these pages (link anybody?) and finally came to the conclusion of "no kids" after three lawyers posted that it was a problem.
As a teacher, your position is public and you are subject to the "court of public opinion". The sorry truth is that a 14 year old girl in the company of grown men, unsupervised by parents, is a situation that lends itself to rumormongering and whisper campaign. Again, I don't know Australia's rules, but here a few upset calls to the district office leads to investigation and trouble. Districts do not want to deal with persistent trouble, and will not back you up.
I also had a group member assault his ex-girlfriend and her new boyfriend. I had to tell him I could not hang out with a violent offender. It was the one of the hardest things I've ever had to do, as he seems like a really nice guy (the assault charge is a complete shock, but completely true.)
I would advise the girl to seek out public settings for play, but I cannot advise playing with her in given circumstances. If she had a parent or older adult relative with her, that would change circumstances in my opinion.