Could it be a chipmunk? She loves bringing those in too!
In the same bathroom, about 6 months ago, I went to go number 1, and luckily I looked before sitting down, there was a 3 inch or so baby chipmunk, that looked like a nearly drowned rat, in the toilet....
My neighbors a quarter mile away, surely heard my scream.... if I had that scream recorded, I could be a multi millionaire from all the movie companies for fright movies would be paying me and using it, for all eternity!!!!
Then I went in to rescue mode... put rubber gloves for an acid wash on, grabbed a handtowel, and got Mr chipmunk out, released him in to the wild.