I think, but don't quote me, she may be or at least have some Fox Trotter in her lineage somewhere. It is difficult to tell specifically by the still photos, but I've seen a good number of Missouri Fox Trotters strutting their stuff
and have ridden 2 different MFT. I did just come back here from viewing a video of a Foxtrotter class to see if I could determine the Mustang mare could be doing a foxtrot. By my visual *guesstimate*
I do think the mare is a gaited horse. It is truly a "guess and estimate".