Equity Release Mortgage on Trust Property?

We have an old trust, with family co-trustee, created by grandfather for a now elderly and in poor health, still spinster granddaughter - the life tenant. A large well known charity is the ultimate beneficiary although trustees have full powers to exhaust the trust in favour of the granddaughter.

The trust has been largely used to assist the life tenant with medical and living costs allowing her to remain in a London property; the remaining asset of the trust save for a dwindling residual cash balance.

Possibly a trust breaking or arrangement might be achieved with the charity to fund the final years of the life tenant in exchange for the property - although some exploration has been made with equity release mortgage providers; so far without success. Appreciating that the available trust powers need to be verified to allow such a mortgage - has any forum member come across a mortgage provider who may be able to assist in these circustances?