If your friend is thinking about using a handheld radio from inside her house (I don't care if it's FRS or GMRS or CB or HAM), she will get just about equivalent range by walking down her street hollering for anybody who happens to be around. And the advantage of the "walk and holler" approach is that she will have many more potential contacts than over a radio.

Now, you can improve range by learning about radio transmissions and installing an appropriate outdoor high-gain antenna. GMRS repeaters are generally few and far between in my experience. I am in the Denver area (suburbs, basically), and there are no GMRS repeaters here that I know of. There are HAM repeaters galore. Hit or miss hitting one of those from inside the house with a handheld (you can hear fine usually, but not trigger them for transmit). Outside with a decent antenna - no problem. HAM repeater use is nowhere near what it once was, but during an emergency I imagine there will be lots of people available for contact. Assuming the repeaters have power.

An FRS handheld from inside your house might be able to talk to your neighbor across the street inside their house, but that's about it. Outside, you might get 1/2 a mile to a mile if you're lucky and don't have hills and other obstructions.

While my "walk and holler" comment above might sound like a joke, it is probably the better and more reliable communication technique for non-radio enthusiasts who don't want to obtain a license and learn about feedlines, antennas (and their need for lightning protection), and such. The actual radio will be the least expensive part of the setup. You could do quite well with a handheld if you upgrade its antenna and walk to a hilltop overlooking a populated valley with other radio enthusiasts (you can't upgrade an FRS radios antenna). But unless you live on that hilltop - if you have to walk to it - might as well just walk and holler.