Hi, coldfusion, welcome to PsychCentral. I don't think you really have a choice; if she wants to continue what she is doing outside the relationship then that's how it has to be for now.

Were I you, I would explore also, not necessarily dating, if you don't want to do that, but career choices and what children and families are like and the "rest" of relationships and experiences life has to offer. You're barely 1/4 into life. Do a little looking ahead to what may be coming up and thoughts you might have on some of it; where to live, what to do, how to make money, how much money you want to make, what car to own; there's all sorts of stuff out there and having an idea of what you like and don't like might help you get a jump on some of it when it comes up. Working on your own projects will keep you from fretting about your girl and what she is doing with her life. The two of you might know yourselves better if you get back together and that's always good; if nothing else, will give you new topics of conversation :-)