Three strikes here: she's straight, she's half your age and it's an online affair. Online affairs are not real. It's all mental fantasy island, which makes it feel so compelling. People in that situation can pretend to be anything you want and you don't have that oh so necessary day to day contact to see if it's real. I'm sorry but you need someone your age whose geographically accessible and out of the closet. Furthermore, she's committed to someone else and that makes you a player in the triangle. Not good, regardless of sexuality. Save yourself for someone who wants what you do and is ready to commit.
