Lisa, she sounds adorable!
I've had many dogs that didn't "get it" when it came to going to the door to go out. They'd stand at any door, regardless whether I was in the room, and they'd wait. And wait. And then it would be too late.
So I tied cowbells to each door handle (except for the front door) and taught them to ring the bells, so I could hear it when they needed to go out. I just grab the muzzle, smack the bell, and say, "Good out!" and then open the door. It takes about a month but it's worth it.
You can get cowbells pretty much anywhere. Don't use jingle bells. They fall off. 
