She looks like a Sabino to me and if so she could be double registerd. The Sabino gene often is mistaken for Roaning. One of the signs of being the Sabino gene is unusual face markings which she sure has that, I love it!
I know the president of the Sabino Horse Registry Sabino Horse Registry and if you send her pictures she can tell you if your filly could be a sabino, her name is Dyan and a wonderfull horse woman, I met her on the foalwatch group.
She may not respond to you right away as we have gotten word that she is without power right now due to the ice storms.
There is also a new DNA test that can be done for the Sabino gene as well.
Let me know what you find out.
Cathy C