Glad to hear she is going to get it tomorrow if she has not passed it.
There is a chance she may have and ate it but with our girls you always use the better safe than sorry approach.
Some vets will use the wait and see approach but thats not the best approach with this/
Here is a link for everyone that does not realize what complications can arise from a retained placenta.
Dam Almost Dies 6 Days After Pups were Born
As a breeder we need to let our vets know that we want to use the safest approach for our girls.