The whole shield maiden thing seems to be mostly myth. TV “history” is enamored with it because we have to keep the “new myth” that women can stand toe-to-toe with men is hand-to-hand combat. I guarantee wearing a shirt of mail (maybe!) holding a shield and whacking with a sword in a life or death environment is not the same as going to Cross-Fit! No matter how much modern young women want it to be so or how many times its portrayed as true on TV.
This is actually what happens when men and women fight:
https://www.youtube.com/watch?v=cxzd7kKm91c
Note that the guy was pulling his punches to avoid doing serious harm to her. If he had been going full bore she would have been down in seconds.
https://en.wikipedia.org/wiki/Freyd%C3%ADs_Eir%C3%ADksd%C3%B3ttir
Leif Erikson’s daughter lived up to the shield maiden myth...
I think TV is enamored of the "Warrior Princess" because the concept generates good ratings. I'm not sure why. Female warriors always seem to be too poor to afford much clothing.