I agree about there being plenty of space. Rather than keep her in her room, last night I let Izzy roam the first floor while everyone else (including the new cat) was sleeping upstairs in a closed bedroom. When I came downstairs this morning she was very chipper and had obviously enjoyed having the run of the place. She seemed back to her old self, so I think this will be a new nightly routine. I don't think it solves the problem of her fear of my husband, but it will hopefully help make her feel more comfortable and at home in the new place so she is able to make progress with him over time.