Cats are very strange creatures of habit and do NOT like change.

A big move such as yours has probably overwhelmed her, especially all the big space you have now. What I would suggest you do is keep her confined to a spare bedroom with her litterbox, food and water for about a week. This will help calm her down and make her feel a little more secure. Visit her and talk to her, giving her treats. That will reassure her. When you feel she's calmer and more content, let her out again to explore. If she still hides, put her back in the room and let her out periodically to explore some more. Eventually she'll start feeling comfortable and will know that you're there to stay.

As far as her reaction the kids is concerned, she was probably intimidated her the little one. Staring is a cats way of letting a person know they feel threatened. If you ever watch two strange cats together, they both stare at each other and then one will look away. A cat's body language is something to be aware of. Especially if the ears go flat or turn back. I'm glad Ally was well behaved. But 3 year olds can get a bit excited over seeing an animal and get a little "rough", not meaning to. I hope this didn't happen and that she was supervised while visiting with Ally.

I wouldn't worry too much about Ally, that is unless she stops eating, drinking and using the litterbox. Then I think it warrants a trip to the white coats. Just keep an eye on her. She'll come out of her shell once she knows that this is HER house and you're not going anywhere.

Glad the move went well and you're settled. Pictures please!!!