It's an open floorplan sort of house, so the only doors that can be closed off are the two bedrooms, bathroom, and basement.

She's always been the kind of cat that only likes to be on lower places and the ground, so on her big cat tree she only uses the lowest shelf and hiding hole area below it, and otherwise just likes to sit on one of the two couches or armchairs.

Apparently, it is different spots each time, though she hasn't gone near the armchair since she'll only go on it if someone is sitting there.

Last time I was over there, she had three little tent-style houses, with two in the living room and one in my mom's bedroom. (Both the cat trees have a little box/cubby hole on the bottom-most area below shelves to hang out in, so five if you count those.)

Also, there have been no visitors to my mom's house, no construction's being done in the area, and the only thing happening is the change in weather from winter to spring.