Aah yep - I know what you mean Have you tried playing music in her room, so there's a kind of constant noise? Perhaps the 'awake' household is disturbing her? It's a tough one. Has she always done it? or is it recent? It could be developmental and could change again next week.

I usually find by the time I've worked out what's causing the restlessness and have a plan ready that it's all changed again LOL.