Also, if she already parks out, then it'll be more difficult to get her to stand correctly as an Arabian. She'll be likely to park out every time and that's not the correct stance for Arabian halter.
To be honest, that chestnut is overstretched in her stance as well as her neck, so I wouldn't be concerned with trying to emulate her. What DreamCatcher posted is far more correct.
The point isn't to just stretch the horse as much as you can, but for the horse to use muscle and work for the position. The "good" halter horses don't practice that stance for long because it's tiring and uses a lot of energy for them. When we had halter horses at the "A" shows, they'd do a quick warmup, setup a couple of times, and that'd be it.
The wind of heaven is that which blows between a horse's ears. ~Arabian Proverb