I have mortgage with my sister, the lender. She is nonresident.
Can I add her to my house deed and take off the mortgage?
Who can do this type transfer? Escrow company, real estate aatorney or title agent.

Attorney.

Is the sister willing, you can't do it at all unless the sister is willing to do it.

Why do you and your sister want to do this?

Yes, she is willing to do it. Sometime she would stay here for a couple months.

I'm not clear what you want. Your sister is on the mortgage, but not the deed?