It doesn't work that way, Cloud. The filly is a frame overo, as well as carrying possible sabino(the roaning) and definitely splash, which causes the blue eye. Here are the descriptions from the Equine Color website:
There is only one form of Sabino that can be tested for, SB1, but many horses that exhibit phenotypical sabino markings test negative for SB1. It is not known at this time how many different genes may be expressing as what we call sabino. Sabino tends to affect the back legs of the horse first. It tends to leave chin white, and roaning along the edges of white markings, and sometimes scattered in the coat. Like any pattern, expression varies. At times markings as small as a star are blamed on sabino, although in truth it is difficult or impossible to tell what pattern a very minimal horse carries without testing. According to the current visual evidence, sabino does not cause blue eyes. Sabino, at least SB1, is an incomplete dominant, meaning that homozygous horses express much more white then heterozygous horses - hence the term "max white sabino" The only breed currently thought to lack sabino is the Icelandic Horse.
Splash, or splash white, is theorized to be an incomplete dominant gene. Splash tends to leave white markings with even, well defined edges, almost as if the horse had been dipped in white paint, starting at the the head and legs. Blue eyes are common with splash, as well as bottom heavy or apron blazes. Splash is associated with deafness, but not all splash horses are deaf. It is thought that deafness is caused when splash inhibits pigment production in the inner ear. A well know AQHA stallion that exhibits splash is Colonels Smokin Gun
Frame is otherwise known as lethal white overo (LWO) syndrome. Frame tends to put color on the barrel and face of the horse, move horizontally, and leave the legs solid (although other patterns can add leg white). It also tends to leave white that is "splotchy," with jagged edges. It is well known to cause blue eyes, but not to cause roaning in the coat. The name "Frame" comes from the pattern's propensity to leave a "frame" of color along the outer edges of the barrel.
Frame (LWO) is lethal in its homozygous form, with the foals being born solid white and only surviving a few days. They are born without a functional digestive track, and unless euthanized, die in gastric distress. Because it is often hard to visually tell if a horse has frame (there have been cases of solid colored horses testing positive), it is important to test breeding stock in all breeds that carry frame in order to avoid producing a lethal white foal.
Frame is an incomplete dominant characteristic and breeding frame to frame does not increase your chances of obtaining a frame foal; statistically, 25% of foals from frame-to-frame breedings will die, leaving 50% frame and 25% solid surviving foals. Breeding a negative frame to a frame will give 50% solid and 50% frame foals. By only breeding non-frame to frame you effectively reduce your chance of a dead foal by 25%. The confusion among some breeders is most likely the result of horses carrying multiple white patterns, such as sabino and splash, in addition to frame.
She does not look to carry the tobiano gene at all.