Rent to Own House Bought For Daughter

Some time ago I purchased a house for which my (divorced) daughter w/5 children was going to pay rent. The object was that eventually the house would be hers.

She has not been able to make any payments and now her children are grown. But she still does not make enough
to pay the monthly $770.00 mortgage which I have continued to pay.

Is any of this, either principal or interest, deductible on my tax return?

Thank you for your time. However, if there is a charge, please do not answer as I am unable to pay anything.