I am right handed, left eye dominant.
I learned to shoot a rifle left handed in boot camp. My right eye is so weak in "wonders" in the dark when it tries to focus on light. This made it impossible to focus through iron sights.
It has now become unnatural feeling to shoot anything (rifle, shotgun, handgun) right handed. I actually find it hard manipulating firearms right handed because I don't have a lot of practice doing it.
I can shoot a rifle right handed, if I have a good scope or an EOTech or Aimpoint and shoot with both eyes open. But it still feels iffy.
Shooting left handed is the best way to go in her situation.