You do not enter the "purchase" of a house on a tax return. If you own a second home, you can enter mortgage interest, property tax and loan origination points for the second home. But you say you are already "maxed out" with the interest and SALT on your primary home, so entering your second home will not help you. If your mother is not paying rent, you cannot treat it as a rental property and deduct anything for it. It sounds as if you are simply being kind and generous to your mom, which is not deductible.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
