sure. by my (limited) knowledge of the 4runner its payload is 1235lbs and your GVWR on your camper is 3700 for a tongue weight around 550
1235-100(hitch)-550 (tongue weight)- 250 (gear)= 335lbvs for your family. This may be inside your range (no idea how large you are) or you may pack less **** than me (thinking coolers and firewood here) but that's awfully close to max capacity for a vehicle that's 12 years old. I don't mean to sound negative and im not saying you cant do it. Just know that its close. Keep in mind the rig in my sig put me rate at the limit also so I know better than most that it CAN be done but it might (wont) be fun.