Knowing nothing about "proper" Western riding, allow me to ask: Is this a standard riding position in Western? She seems very far back in her saddle, her feet out in front of her. Does that not create a risk of being "left behind" if the horse accelerates?
Take this with a big steaming cup of FWIW, since I'm a self-taught rider...
First, many western cantles are 4" high. Some are 5". The old western saddles often went higher. One in a museum had a 9 inch cantle! It isn't like a jump saddle or even my Aussie saddle. You don't feel like there is a big risk of sliding off the rear.
But for proper riding, your legs move to where they can help you most with what you are doing. With a green or spooky horse, or riding in a place where your horse may throw it in reverse or stumble, then heels forward with a long leg can be a very good thing. Any unexpected slowing or stumble just drives you into the stirrups. Crow hops are pretty easy to ride like that, too.
If my horse may spin, then I feel best balanced with my heels under my hip. That puts my weight further back, which is what the horse does when he spins. It also means I simply rotate around with the horse. My position matches the spin. Seems to work well for a western jog, too.
For normal riding, I like what the British Cavalry taught in the early 1800s: that the heel should be just in front of a plumb bob dropped from the soldier's chest. That gives me the option of sliding my feet a few inches forward or a few inches back very easily. I think of it as the equivalent of a tennis player trying to stay near the center of the court. Not all balls come down the center, but you don't want to be far to the right when the ball goes far to the left!
As speed increases, most western riders adopt a forward seat. Longer leg, but heels and shoulders come forward to match the horse.
In a show, a lot depends on the type of show and the current ideal. This was considered good reining form in 1987, but would freak people out today:
My favorite saddle's resting, "neutral" position puts my feet forward. For the horses I ride and where I ride
, that is fine. It is like when I visited an old friend on a ranch in Utah last summer. I asked him the proper way to do something. "Out here
", he replied, "there may not BE a proper way. I can show you how I like to do it, but others do it differently and get good results.
I'll never cut cattle, but my horses have tried to cut garbage cans, so to speak. This video is closer to what I like in western riding and riders. It would make no sense in an equitation class but has worked for me when my horse has swapped ends in a spook: