Skin prick tests in under 1s are grossly inaccurate, a lot of docs don't even bother doing them before 12 months as you can get negative results even when they do have an allergy. When Spencer went onto neocate the doc didn't do a skin prick test he just went on his case history, he went on it at 4 months but wasn't skin prick tested till 12 months when he showed positive to dairy, egg and peanuts.
If I was you I would wait till Friday, a few more days won't hurt, and then try it in baking first or the condensed milk in tea again (although that sounds really gross, evener grosser than the rice milk in tea that I tried
) and see how you go. It sounds to me though like she does have an allergy to it and I also would be reluctant to put her on cow's milk formula but you should be aware that goats or sheeps milk would also be unsuitable as the proteins are too similar and there are issues with the soy one as well, I can't remember exactly what but if you google it you will find out and also the tin itself says to only use under medical advisement, so if you are going to wean you really want one of the prescription formulas but the paed would need to think she has an allergy to give you the script (gps can't get the funding it has to be a paed).
Good luck