<human>: Hi folks,
    When I  was in my early twenties, I took out a 30-year fixed 4.0% mortgage to help my family buy our house.  The mortgage is entirely in my name but the deed has both my name and my mom's name. For the past 10 years, I've been paying half of the monthly mortgage payment and my mom pays the other half.

I was told by my accountant that I'm 100% entitled to the tax deduction from mortgage interest because the legal responsibility of the mortgage is entirely in my name.

My question is this: What if my mom stops paying her half of the mortgage? I could pay the monthly mortgage payment by myself for a while but I would be struggling if that happened.

What are my options? Can I sell the house if she doesn't pay her half? Can I sue her to get her half of the mortgage? 

Am I just outright screwed?

Can you condense the text into a few key points?
<bot>: My mom may withhold her half of the monthly mortgage payments from me. The mortgage is in my name but the house is in both of our names. What do I do?