Just wondering if anyone might have some ideas.

My little girl is 3.5 and for the last few days she's been extremely sensitive and just starts crying at the slightest provocation. Can be happy one minute and in tears the next. At kindy yesterday they said she wasn't herself all day, and today she's the same. She doesn't seem sick or anything, she says she feels fine.
She's also been talking alot about our old house and our cat who stayed behind with the new owners - but we moved from there 9 months ago and I can't even believe she remembers it! When we lived there we had a pretty quiet life and a fairly samey routine because the kids were so young and she is a creature of habit and has always thrived on routine since she was quite young.
Right now things are a bit all over the place and have been for a while - I am in and out with no predictability for client visits and births.
DH thinks she is missing the security and predictability we had at our old place, not so much the house itself.
My poor little girl she is always so happy go lucky, do you think this might be the problem (or any other suggestions as to what it might be?) and if so how can I help her feel more secure?