Gina, you probably know all this but I'll post the link here in case there is something you haven't thought of, for for others that have a similar problem:
http://www.yorkietalk.com/forums/mis...ir-owners.html
Now, if you haven't already done so, take that dog to the vet asap and at least do fecal sample (if there is any chance it might have parvo etc. it could kill every dog in your house). Did you already have her scanned for microchip?
How did you determine it to be 2 months old (just curious, I would have guessed older).
Be very cautious about letting her around your doggies, especially with expecting delivery of pups any minute now. Yikes.
I know things are different in Spain, but general precautions are warranted anywhere.