OK, I think she is dreadfully in the wrong, but I have been in this situation with my now Ex,
An Ex girlfriend was writing to him through a mutual friend and he was in turn passing the letters on to Ex. As Ex didn't have the 'motivation' to give her a clear message that her attention was unwelcome, she reached a point where she wrote to him and asked him to put a friend of hers up for a while. (He and I were living together and he actually showed me this letter, the others I knew about but didn't see)
So I wrote to her, and as 'gently' as I could explained our living arrangements, and that if she still wanted she could still forward her friends details, or she could get in touch with an organisation that dealt specifically with her friends hobby, as that was why he would be in the area)
I really did try to afford both myself and her some dignity.
I wonder if you did the same, so she is clear that there is an existing relationship and that you happily share each others phones, she will be able to back out graciously.
This might bely how you actually feel but I felt better for not being too 'possessive' (although I felt it, it caused a lot of problems, which to be fair were 80% his fault, but that would be another story)