My mom wants to add me to the title to her home which is paid off. What do wee need to do?

Why? If you trying to avoid probate there may be better ways.

If she puts you on the title, she will be gifting you half the value of the house and there may be tax consequences to doing that.

At the top of the Real Estate Law Forum there is a sticky post that explains how to add someone to a deed. You can read it at https://www.askmehelpdesk.com/real-estate-law/how-add-someone-your-deed-569716.html