Of current HCs 21 are former NHL players- and most of the rest played up to pretty high levels, either NCAA, major junior or minor league hockey. The only one with no significant playing experience is Cooper who quit playing in high school and later worked his way up the ranks from coaching high school, to NAHL, to USHL, to AHL then NHL with incredible, possibly unprecedented team success each step of the way.
If a female is going to HC we’re probably going to see her coming as she moves up in the ranks like that. I think to start we’ll need to see way more assistants at the junior, collegiate and minor hockey levels and then see where they’re at in a few decades. Gonna be a while though.
Obviously being a good NHL coach doesn’t require being a good NHL player but that experience seems pretty important. To get your foot in the door, learn from other NHL coaches, who knows.