Never judge their intentions from their words, actions are what matters.
What I'd do is ask if she wants to do something. If it feels 'right', I'd suggest we go do something right then. If not, I'd ask for her phone, call my cell on it, and say "how's Saturday for _____?"
The idea is to get her name and number. If you also manage to get plans out of her, great! If you don't, no sweat, just chat her up on the phone a little and ask her to hang out then.
In your case, it sounds like the girl's not in the 'serious' mood so I'd avoid pushing her for a 'proper' date and, instead, make friends-ish plans. Just, whenever you hang out with her, invade her personal space some, bring up sex (subtley), and make sure you both have fun!