That phrase comes from a man who was not easily impressed.

Denig spent twelve years around some of the most skilled equestrian warriors in the world.

When he said she could rival any of the young men, he was making a specific comparison to people of extraordinary physical capability.

The question of why her father encouraged this path, and what he saw in her that persuaded him to do so, is something the historical record cannot answer definitively.

What it can answer is that his encouragement worked — and that the capability it developed would define the rest of her life.