Sounds like an Enduring Power of Attorney, and I know there were recent provisions to facilitate that. It's not so much "without her permission" as "in a situation where she is no longer able to give informed consent". She'll need to discuss the implications carefully with her solicitor, but it is a useful tool.
For example, if in a few years' time she were no longer able to live alone, and had to go into a nursing home or long term care home, and at the same time was becoming senile, you could end up with a situation where her house is unlived in, she can no longer give informed consent to the sale, and so effectively nothing can be done with the house, even though selling it and using the funds to give her the best care possible would presumably be the most sensible thing to do.
I think there are also safeguards so that the funds must be applied on her behalf or as stipulated in general terms in the enduring power of attorney.