I have known of Habitat for Humanity for several years and this is the first time I've ever heard they have some sort of relationship to a religion of any sort. That is exactly how little they advertise religion when helping people. They've built several houses in my area and I didn't even know they were religiously affiliated.
The grandmother should be built a custom-made shed in the back yard, then they should burn the shed and then let her live in it. She seems like a real turd.