Can she take me off the deed

[AWheeler]

I am 50% owner of my house with my mother. She owned the house outright up until 3 years ago when we had a fire. She did not have enough money to fix the house and the insurance she had only paid the mortgage. So, I put my money into helping her get the house fixed etc...with the agreement that I would be 50% owner. I am currently on the deed as 50% owner of the house. She and I have had an argument and she threatened to take me off the deed. I want to know if she can legally do this without my permission.