Not sure if it's been brought up yet, but the smaller her tow vehicle the more likely that trailer is going to push her around. I'm not just talking about braking because trailer brakes will help with that. I'm talking about bumps, curves, and definitely the wind.

For what it's worth, my truck is factory rated at 410 ft. lbs. of torque and pulling a 4,000 lb. trailer up across the mountains is about all I can do comfortably and easily. And that drops my gas mileage down to about 11.