Hi Jim
What are your plans? Are you living in the house at the moment? Would you prefer to continue living there? Can you buy her out?
How much equity do you have in the house? I think you can sell your interest in the house to her and I am not sure that you need the bank's consent. If you do need the bank's consent, you can give her an option to buy your interest in the house for its current value. She would execute this when she is able to do so. You would also have a put option, where you had a right to force her to buy the house or sell it.
Your name would remain on the mortgage but she would pay it. However, you would be liable if she did not do so.
The cheap tracker mortgage is so attractive that you should be doing all you can to keep it. At the same time, if you both want to move on, you should stress to the bank that they would be replacing the cheap tracker with a Standard Variable Rate mortgage, although with only one name on it. If there is positive equity, they should go for it.
Brendan