I know she's got a boyfriend, but do you think I should take this any further?

People who are taken are always difficult to read; you never know if they like you too - believe me I know. There could be a possible chance that this girl likes you as you like her but you have to also consider the other possibilities. It's all well and good that she may like you but you've got to take in the fact that she has a boyfriend whom she has been with for a long time. Would you really want to get in between that? And, as you've said, this boyfriend is moving away to Australia and she has told you that she won't be moving with him, could there be a possibility that she's trying to get close to you because she doesn't want the fact that her boyfriend is moving away to hurt as much if she has developed feelings for another? So, my advice is that you leave it for a while. Move on would be a very sensible and noble choice. Just be a friend for her, comfort her when her boyfriend moves away and hope that maybe she'll want to progress to more with you once everything has passed. I hope for the best.