It's great when a situation like this works out as well as Julie and Dreamer's, and part of their relationship, I think, is mutual maturity and honesty from day 1. However, to be honest, it usually just turns into a messy situation. You need to be clear if this is "broken up but both are free to move on" or if there's an element of sneaking around and "not quite broken up". There doesn't seem to be enough information to tell.
If you just met,
You may not have enough information on this girl's character, let alone if she's truly your great love. All the better not to get too enmeshed and just see how it goes.
Trust your deepest instincts, and don't make excuses or let this girl pee on your leg and tell you it's raining. Get to know her before you get your heart involved (that's for any relationship, actually
).