She is just amazing!!
Ok so first question, does she have a roan parent? With out a roan parent she can not be roan, however sabino can mimic roan as well as LP ( varnish)
Ive found ( so far) all my roans are *born* roan meaning that after a few days if I part the hair on the top of the back I can see very short roan hairs coming in. Almost looks like a few gray hairs , wiggly like ours!! ( or mine!)
I have heard, but not personally experienced the roan showing up after the foal sheds the first time, however I suspect it was because they just didnt notice the small gray hairs coming in by parting the hair, but its possible!
Kate my welsh is roan and has produced roan foal 4 times in a row then came Tux, looks to have no roan, but I will be thrilled if he roans out at his first shed!
So I suggest part the hair at her darkest area, if you see roan you know she is. Can you post pics of her parents for me?