Omigosh, I have to say it, sorry, but she is deceitful and she doesn't value or respect you. You said you are advertising, so fill the space and whether they want to stay or not is not the point. YOU should decide when it's time to let go of clients you CANNOT trust, and this is one of them.

I have a family who are just thinking of selling their home and moving to another part of the city but they have already told me about it and assured me that they are staying with me because they were concerned that I would see the For Sale sign and worry. My daughter lives on the same street as them and I would have been worried. But I also would have asked them immedately when I found out, so I'm very happy that they value me enough to tell me before the fact. YOU deserve families like that too!