First of all, I would advice you to stop looking at this as a "date", because it will make things harder for you this first time and everytime after. Don't make it sound too formal for her; play it as a very down to earth thing to do. Invite her to get together, or to join you to hang out. Doesn't have to be anything fancy, or that has the "date" connotation.
Women really invest a lot of time and energy into "dates", so accepting such an offer from somebody new might really cause her to really consider wether its worth to go through the whole process, let alone what it will do to you. If there's a chance that she will want to get out of it, she will. Women put too much emphazis into these kinds of things, and try to find what it means.
Play it more casual, that way you can "screen" her and see if you even want to keep seeing her again; makes both sides be more confortable and things go much smoother into an eventual "date." Invite her to join you on something you are already have planned; so have something planned. Keep it low key. If things go well, plan something for next weekend.
To set up this kind of get together, you don't need to ask her that far in advance. I would call her sunday, probably late afternoon and ask her to get together. Don't ask her if she wants to go out on a date. Don't give her any chance to hesitate by the prospects of everything attached to a typical date.
Here's a plug for my latest post on the TIPS section:
"ACTION DATES" Ideas
