I would not pay anything for the repairs, no way. Are you in a position to buy the house from her now?

It seems like it would be better to just cut your losses and move on entirely from this deal because you can't really trust what she says. She said you could buy it, but now she isn't selling. She said you could fix it, but then she took over and paid more than you would have. The market rent you are paying - is that more than the mortgage payment? I think there's a danger that she will say you can close on the house in October and then pull the rug from underneath you again. I'd let her deal with everything including the hassle of selling to someone else. You are in a great spot to look for a new place since you can break your lease whenever you want. Oh, that must be so annoying, to have her treat you like a tenant while she still acts like a bossy mother instead of a landlord who has to abide by the lease and provide a habitable home.