Here's the situation:

She was a drop-dead gorgeous 14 year old new-hire at my workplace where I was the boss. Being too young to game, I tried to keep up kino and flirtation to try to keep out of the friendzone for later. We partied and drank quite a few times and she'd talk about her sex life with me all the time.

Flash forward to a few weeks ago:

She's now a first year university student, 18 and a solid 10. We ran into each other at the mall and she practically knocked me over giving me a hug. She was preening and showing many IOIs and talking about how she's all grown up and wanting to drink and party at university now, and how we should get together and party sometime.

Where do I take this to finally F-Close?
Is a close actually going to be possible here?

P.S. Our typical party location is in the apartment of an old co-worker, while always fun, it's such a close knit group and also such a small location that getting any personal time to kino/escalate is gone.