When we asked my DSis, DBIL and my nieces to join us, we told them up front that we would provide the room, but since our points cost us money, we felt it would be fair if they paid for one of our sit-down meals. Since my nieces really wanted to eat in the castle, I got up at 4am on the day our ADR window opened and made the reservation. My DSis had a check in the mail the next day to pay for the meal, because we had to pay for it when I made the ADR. They also paid for half of the grocery delivery so we could have breakfast in our villa every morning. Needless to say, we've told that sister that her family is welcome to join us anytime they're interested in going again.
While I think it's great when someone uses their points to gift a trip to family, it kind of sets up the expectation that the trips don't cost anything. By putting a price on our points from the very beginning, we've never had to worry about family expecting us to give them a room whenever they want it.