We had a similar problem, but I resolved it with sensible discussion, it never went to court. My father owned a near derelict house, which he allowed a JW family to live in, rent free, until he needed it.
The crafty bugger tried to get the old feller to accept rent, but dad would not, knowing this would give them rights, plus he would have seen a couple of months rent and no more, the "brother" had money troubles, which was why he was on the street with his wife and two kids.
When father wanted the property back, matey boy, who by now was back on his feet, running amuch better car than Dad had etc etc, did not want to vacate, but I persuaded him it was a good idea (Don't ask)
I also said that if he bad mouthed the old man I would take him to court, so he never had a bad word to say about Dad, which knowing him he would otherwise have.
I guess we don't know all the facts of this case, but even if the owner did promise them a lifetime tenancy at a peppercorn rent, the judgement seem awry in the present circumstances, I hope the old lady wins, and the JW's will have to live at least a bit in the real world.
Anyway, they won't have to pay a fair market rent for long, the "End" is soooooo close !