A slide sheet could help to move the person’s legs when getting out of bed. I assume she has a bed loop or lever.
Getting the legs into bed is more difficult. Multifit has a powered leg lifter but I doubt the rest home would buy it for one person.
A height adjustable bed would mean the bed could be lowered so the person did not need to lift her legs so high. Using 2 staff and a towel under the legs is an option but could be risky.
The hoist sounds the safest especially if the person is not trying to help. I think there are some special hoist slings for lifting legs but they may only work with a ceiling host. Usually if people need a hoist regularly they are hospital level care.