Well, thank you for coming back, Mrsemmapeel10, and sorry for assuming that you were one of those posters who post once, receive lots of replies but never respond.
I’m a little confused as to how you know that she’s a bit of a cadger and user if you haven’t heard from her for so long and then only knew her vaguely- was she like this then, or intimated these things when you recently met for coffee? If she is like this, I can understand your reticence about going for the meal and continuing the friendship.
I suppose you have two options really:
1. cancel the arrangement to go for the meal, without going into detail why but perhaps have ready an excuse that something unexpected has come up relating to a work/social event that is going to be taking up your time for the foreseeable and be non committal about re-arranging if she becomes persistent. Just say, if she persists, that you can’t make any plans.
2. Go along to the meal, take flowers as suggested, but commit to nothing regarding going forward, just keep it very vague.
I think, though, that as you really feel very uncomfortable about going, then you should take option 1.
Good luck.