What are you feeding her? When are you feeding her? Are the BMs normal? Does she know she's doing it or is it just coming out? Has this happened the whole time you've had her or just the last week.
Using a crate is a good idea. I'd also think about changing her feeding times and establish a routine that minimizes night BMs (no food after early afternoon). The idea of having her checked out (especially a stool check) is also a good one. A different food might also help.
That's kind of throwing out lots of different ideas, one or more may be useful. I'm sure others will have some more ideas.
Doug, DVM