ewww....I would NOT do this! Then she might ask for more things to slide as well. I would not chance it, and would rather loose this parent then to give her a discount.

OR, what I suppose you could do, is to write out a loan system type of thing. So, I would ask for what she can pay for, and then when dumbass dad finally comes through with the money, that's when she will provide the money back to you. Does that make sense? It does in my brain...but it's 9 p.m. on a Friday...

But my opinion, I would say, NEXT!