Taxe D'Habitation

[Lanark Lass]

I have a friend who loves her flat (maison secondaire) in Port Vendres and visits for a few weeks each yeat, but she is finding the combined taxes quite high. The lady's daughter lives in the house most of the time (she has no other home and on a low income).

Could my friend "rent" the flat to her daughter who would then be on a low income for tax hab purposes - or would that be difficult to do or bring other complications?

My friend is in her eighties.

Any guidance gratefully received!