Well, worming her would have been my suggestion as well, but the accidents outside the box are caused by stress as well, especially considering the changes and timeframe with which this started.
I would suggest adding Cat Attract additive to her litter box and making sure it is clean and in a private area for her and even consider adding a second box. Also clean all areas with a good enzymatic cleaner such as nature's Miracle, and if she has a favorite spot, put her food bowls there if it is feasible. You might also add a Feliway Diffuser to your home to help reduce her anxiety from the move and new environment. It will help her feel less like she has to claim the new home as her own, and feel at ease that there are no others that are trying to take her space in this strange place.
If she has been wormed before, have your vet check for Giardia
. I think it is unlikely, but it is possible she may have one of these conditions and they would not be apparent to the vet unless he is looking for them. Now, before you do that, if you are feeding her canned food, take a look at it, especially if it is a fish variety. You may just find that there are white specs in the food that she is passing undigested.
I hope this helps you, please let me know how this goes. I will always be here if you need to discuss further.