Bear in mind that for Inheritance Tax purposes, your mother will not 'lose' the house from her estate at any time in the future, if she continues to live in it (and thereby gets a benefit' from the house), UNLESS she sells it to you at a fair market price and then retains no right to live in it, and rents it from you on a purely commercial basis at the going rate. Check carefully on the IHT rules on this with HMRC and/or a qualified tax specialist who is skilled in the rules affecting IHT. Such a sale needs to be seen to be an 'arm's length' transaction, where there is no evidence of a pre-arranged plot to fiddle the system by doing anything more intricate than a 'no-strings-attached' sale.
As for trying to remove the house from her estate in case this protects it from future care fees, you need to play this very carefully. I suggest that you consult a specialist in the benefits system.
I would imagine that each case tends to get examined on its merits, with, for example, a fit 50 year old having little problem of disposing of his/her house, not normally seeming to be trying to deprive the system of the value of the house to cover the cost of care, while a frail 90 year old would immediately ring mental alarm bells!
In between is a grey area where records of multiple past similar cases and how the law was eventually applied to them may go some way to clarifying the expected outcome. But be prepared for argument over the interpretation of the rules in any individual case.