If someone does get the right ( through the Court of Protection) to deal with the lady's affairs, the Court may be prepared to make a will on the lady's behalf. That way, you find out what you can and can't do. But I warn you, being a deputy is a very onerous job. If there is a lot of money involved, you may have to pay for a Bond to cover risk of loss of the assets, which itself is expensive. Two or more people can share in the deputyship, and help each other. A solicitor can do it, but the fees might well be eye-watering.