Mom's Waffling About Leaving Us

[Dayhome Mamma]

I would go ahead and interview and say this spot is pending depending on the leave of one of the children and that you will be able to confirm its availability by XX if the new family also is very interested in the spot. That way if you meet a non desirable family you have an out, or if you meet a better one than you can move on swiftly and let this lady know that you need her decision by xx as you have another family in line to start xx if she is unable to continue, and that you need to know by xx.

[mom-in-alberta]

I would go ahead and interview and say this spot is pending depending on the leave of one of the children and that you will be able to confirm its availability by XX if the new family also is very interested in the spot. That way if you meet a non desirable family you have an out, or if you meet a better one than you can move on swiftly and let this lady know that you need her decision by xx as you have another family in line to start xx if she is unable to continue, and that you need to know by xx.

I would do exactly this. Begin looking for someone to fill the spot. Give mom an exact date that you will require an answer by, and if you haven't heard, I would have to say that means she is leaving.
You don't have to be rude or angry, but she can't just leave you twisting in the wind here. Otherwise you will find that she gives you notice, and you're left scrambling to fill the space. I suppose in that way, it's good that it's only a p/t slot. Based on what I am seeing, I don't see how they could stay, if she is that allergic. Only one course of action... sad though it may be for you to say goodbye.
Good luck, my dear!!!