Well, then I'll allow my (perhaps extreme) bias to show, and recommend the FEH.
You're likely to see a greater savings over time than against a HiHy, and it's not like it's a vast reduction in space like moving to a sedan hybrid. It'll be far more fuel efficient, it's got a fair amount of neat tech, and if she's willing to learn how to drive it like a hybrid rather than just another gas guzzling SUV, she can get some fantastic MPGs out of it without much sacrifice, and it'll offer space enough for your needs.
I had a '95 Explorer that I figure was getting 16 MPGs, and had a max range of 280 miles on around 16 gallons. Going to the FEH, I actually picked up Horsepower, interior space (and lost a few inches on the exterior), and can go around 500 miles between around 12 gallon fill ups. I've got a spreadsheet that I have been carefully maintaining, so far I've saved $1,209.22 in fuel in just 7 months over the Explorer! Also keep in mind, gas prices aren't likely to be going down anytime soon, and so far the "experts" are proclaiming over $3 a gallon by summer.
Something to think about.
