Nah man, this reeks.
There is a similar case in my extended family.
A caretaker was brought in by the family to take care of the old lady who was widowed. Her son lived in the city and she lived in the village, refused to move to the city. Son died prematurely, heart attack or something. His kids were minors, old lady visited/lived with DIL and grand kids on and off, till she died in the late 90’s.
Caretaker who was being paid to live with her and take care of the property continued to live there. He “negotiated” a rent free system in exchange for continuing to take care of the property. They moved from a shed into one floor of the house.
Now that the old lady’s grandson is asking them to vacate, the descendants of the caretaker are claiming ownership and bringing up her verbal “will”.
What a shit eating world we live in.