In the state of Washington opening your door can be (and often is) considered by the cops to be an invitation to enter. Your best bet is to speak through the door like she did. Too bad she didn’t have a more secure back door.
In my home the person who illegally entered through the back door would be lying in a pool of his own blood and I would either be dead or in jail...
This is in Kah-lee-Fawn-ee-ahh, and they are required to obtain permission and that other dweeb without LEO credentials doesn’t belong on her side yard her front lawn.
Lawyer up.