Which kind of RV to buy for our situation? Details...

Her age??? What do you have to tow with???

I would suggest a bunkhouse travel trailer in the 20'-25' range. That would get them a queen bed and probably two bunk beds. One bunk could be used for a storage area. And a trailer that size should have a regular bath with shower and a kitchen area. A slide out would greatly increase livable room.

Look at rvtrader.com or similar web site. In the filter, put in travel trailer, max length 25', max price $10,000 (or what ever your upper limit is), and see what comes up.