We did have one minor set back this morning - she peed outside the litter box on the sleeping bag we've been using to nap in there with her. Not sure why this happened - the sleeping bag has been in there for 3 days. Cleaned it up real good, removed the sleeping bag (for now). She's used the litter box 3 times since... This was only the 2nd time she ever went outside the box, the first time was the very first morning.
Oh well, still ahead of schedule in my opinion :)