Thanks for your question. I will try to help.
The mortgage agreement does not matter.
You need to download a copy of the land registry title register for the property. It will list them both as registered proprietors of the property at section B.
You then need to confirm if which way they held the property. It can be as either (1) joint tenants or (2) tenants in common please
You can check by downloading a copy of the register for the property from the Land Registry by paying a £4.00 fee:-
Look at the proprietorship register of the title you have downloaded from the Land Registry (where the proprietors of the property are listed). If the following entry is immediately below the named registered proprietors then the interests are held as tenants in common:-
" No disposition by a sole proprietor of the registered estate (except a trust corporation) under which capital money arises is to be registered unless authorised by an order of the Court"
If there is no such entry then the property is held as joint tenants.
If the interests are held as joint tenants then your son’s share would pass automatically to her as the surviving joint owner. This is the case even if your son had a will which said that he wanted it to go to someone else.
If they held as tenants in common then your son’s share would pass strictly according to any Will that he had or (if he did not have a Will) under the intestacy rules. If he held as tenants in common and he did not have a Will and was unmarried and without children then his entire estate would pass to you as his parents.
Please accept my condolences for your loss.
My goal is to provide you with a good service. If you feel you have received anything less, please reply back. Please remember to leave positive feedback using the stars at the top of the page.