Heh..... you think she might be appy?
I don't remember striped hooves... she looked like a minimal white Paint.
That's what struck me. She appeared to have appy characteristics. Those mean an app somewhere in the background. Or a quarter horse mare that throws apps. The quarter horse registry just changed it's regs I think to allow registering excess white, although that wouldn't carry over to app coloring. The app registry will not register excess white.
However, unless you are going into the horse business and want to start selling horses, it doesn't matter if there are papers or not.
I've always thought that the paints that have the ragged edges on their color (like that one that was in the tv series about the pony express) were part Appaloosa.