Can I claim the real estate taxes on my mother's house that we live in together if I am the Trustee and beneficiary of her irrevocable trust and she is my dependent?

[claret]

I claimed her last year as my dependent because I pay much more than 50% of her expenses. The house is paid off and the only thing in the Trust.

[PattiF]

Yes, you can claim the real estate taxes that you pay for the house that is in the irrevocable trust. 

The IRS states that real estate taxes are only deductible by a taxpayer that is legally required to pay the taxes AND actually pays them. 
 

If the trust requires you to pay them, then you can deduct them.  

You can deduct real estate/property taxes that you pay for the property that you own.  If you are the beneficiary of the Irrevocable Trust, then you own the home and can deduct the taxes.

Please see this TurboTax Help article for instructions for entering the real estate taxes in your return.