Each trip we ask my parents to come and visit (they live in Avon Park half the year). I also let the gate know (via the hotel desk) as well and they have never had a problem parking at the resort either. We have done this at YC/BC, POR Riverside, FQ, CBR. This trip we will have my sisters stopping in for a day as well. They always spend some money while they are there and we use the restauants, so Disney profits of course.
Having said that, we always talk to the front desk CMs to be sure. They have always been gracious and eager to please on these family matters. And we do not abuse this either.
Artemus