Im sorry, but I think thats ridiculous. You HAVE been acting like friends. Are her 19 y/o friends giving her advice here?
I would be really on the lookout for her trying to initiate a fight during this time, make sure that you dont take her bait! She cant have a one-sided arguement.
Shes holding all the cards here, I dont feel good about her week of experimental friendship. You have a history extending at least 9 years, Im basing it on the age of your oldest child, and she wants to make a decision about it based on a week of behavior! Be careful (and guarded!) here.
but what i dont get is she is the one who is so dead set on being friends. its something she keeps asking for