I assume the house is worth more than $50K or it was a major error to pay her credit cards rather than just bankrupting the estate. If you were a joint tenant on the house (the deed says, "Mom and Daughter, as joint tenants" or "M and D, jointly), you already own the house 100% without probate so you would meet all the IRS tests to deduct the mortgage and taxes but NOT the "bills." There is a possible issue that the two IRS Forms 1098 from the bank and city will be in your mother's name and linked to her social security number. This problem comes up frequently, usually from divorce or death, and I have never had a problem with just attaching an explanation that your mom is dead, you now own and live in the house, and that you actually paid the money. You can only deduct what you actually paid so I'd attached your checks or bank statements showing that YOU paid the mortgage and taxes which you are deducting.
This is just a general statement of legal concepts based on assumptions that could easily be incorrect. I'd need to talk to you in person and review many documents to give you legal advice. Please see a lawyer about this. You should be able to find a lawyer to work for an hourly fee, and not a share of the estate. I estimate you need under 5 hours of advice which could easily save you many times that in tax benefits before the estate closes.