When my mother married her husband he opened a bank account in both their names but the majority of his money was kept in an account in his name only. After 16 years of marriage would she now be able to claim half of the bulk of his money. He is very frail now and may need to go into a nursing home but my mother is still very active.
I think if he disposed of the money in his own bank account now and he needed to go into a nursing home, it might be deemed that he had done so with a view to trying to avoid paying his fees there and he would still be charged. I'm unsure what the savings limit is before residents have to pay for their own nursing home fees but if you check the Age Concern website you will find they have a lot of useful Fact Sheets about having to pay for nursing home accommodation which you may find helpful.
Your Mum will need to see a solicitor regarding an 'Enduring Power of Attorney'. Be advised this can only be done if her husband is still of 'sound mind' and he agrees. It will allow her access and control of all his affairs, including financial. If he is not of sound mind then it will probably be necessary to become involved with the Court of Protection. Avoid this, if possible, as it can become expensive.
You can do an Enduring Power of Attorney without a solicitor, but you need to be careful to understand how to complete the form properly. Go to www.guardianship.gov.uk where you can download the form and a booklet, which is essential reading before you go ahead.