3500 lbs is what she can tow...to keep it safe try to stay under 2500 lbs, some of the very light weight Alinerpop-ups would work great, especially if she plans on camping minimal persons. A small tent type folding camper might work, too! Like this 2500 lbs.
Some of these Fleetwoods are around 2500 lbs too! Good luck!
Take your GVWR and subtract your actual weight (go to a truck stop and get it). This is how much stuff you can load in the Nitro. Take the GCWR and subtract the actual weight (after calculating all that stuff you added to the Nitro). . . this is the max you can tow, assuming the tongue weight isn't too much (which it shouldn't be with a PUP).
All of this is assuming that they have the factory installed tow package.
I'd be more comfortable pushing closer to my full tow rating with a popup camper. . . they don't have the wind drag that TTs do. I've always had great experience with Fleetwood PUPs, and I've also been impressed with Starcraft.
2005 Chevrolet Silverado 2500HD Crew Cab SB LS 6.0L 4x4 4.10
DW, DD (May, 2007), DS (October, 2008), and me
Thanks all. I just got back from a business trip and am checking in. This will get her started. She does NOT have the tow package but assumes she could get it put together from the dealer.