[crick]

Personally, it's not something I'd work on right now. Sounds like a bit of a control situation with her combined adjustment to a new family and home. Although I agree with Diane on ruling out any medical problems first.

I'd work on other things right now, like bonding/attachment and leave the potty training til later. If you don't make an issue of it, it stops being a control lever for her. She can wear pull ups and when she makes a mess, she can clean herself up (might need a little help from you on some clean ups, but she needs to be responsible in cleaning up). Don't say anything other than things like "oh, you know where the pull ups are, and here is a washcloth to clean up" Getting a reaction out of you is a big part of it.

I wouldn't give her a consequence other than the cleaning her messes. It directly applies to the situation and in my opinion, kids learn/respond more to things directly applied, not things like missing dessert for something they did earlier in the day. Not at that age anyway...they don't grasp this well enough to get the message.