There are a number of legal issues you may have to consider when caring for someone. This may include Power of Attorney, Lasting Power of Attorney, Court of Protection etc.
Power Of Attorney - A Power of Attorney is a legal document which gives the authorisation to another person for a persons financial affairs. The Power of Attorney is limited and is valid only while the person whose financial affairs are being handled is fully compos mentis (sound of mind). If the person you are acting on behalf of becomes mentally incapacitated the attorneyship becomes invalid. There are two types of Power of Attorney:
Lasting Power of Attorney - This has taken over from Enduring Power of Attorney. The lasting Power of Attorney gives the person who is appointed to manage the affairs the right to make not only financial decisions but also welfare decisions for the person is being cared for.
Court of Protection - The Court of Protection makes decisions for people who are unable to do so for themselves. It can also appoint someone (called a deputy) to act for people who are unable to make their own decisions. These decisions are for issues involving the person’s property, financial affairs, health and personal welfare.
Wills - By making a will you or the person you care for can decide what happens to your property and possessions after death. Although you do not have to make one by law, it is the best way to make sure your estate is passed on to family and friends exactly as you wish. If you die without a will, your assets may be distributed according to the law rather than your wishes.
Trusts - Trusts are a way of looking after assets (money, investments, land or buildings) for people
The Citizens Advice Bureau Adviceguide have a excellent advice guide which will give you background on some of the above.