While I've been a strong defender of treating characters and concepts and such appropriately compared to their source material, at the same time I'm also a strong proponent of development and things changing over time. Just as in real life, people can and do change. Even after reaching adulthood, nobody will remain entirely the same person after ten to twenty years have passed. People can and do come into new ways of being that would surprise people they knew a decade prior. The key when using it in fiction is that you need to actually see it happen with your own eyes.
More importantly, times change. Social expectations change. Clothing that would have been seen as disgustingly inappropriate back when these comics were made would, today, be seen as not only totally acceptable in fiction, but even fine to wear in everyday life.
The suggestion that characters "can't" develop into better, more appropriate modern ones just because they were originally conceived a certain way would mean that nearly every major male character in comic books would have to be a misogynist or a racist. Superman would be talking about slapping Japs if one of the villains was asian. Batman would straight up murder petty looters and shrug it off as just desserts. Wonder Woman comics would be endless streams of BDSM fantasies with women getting tied down every issue (for clarification I am NOT suggesting those early Wonder Woman comics were sexist, I'm just using it as an example; I know full well on Wonder Woman's creator's views on women). Sue Storm would still be called Invisible Girl and Reed Richards would essentially own her. Just because a character was conceived a certain way does not mean they're absolutely required to remain that way. They don't need to become the exact opposite of their origins, but there are certainly things that can be altered, a middle ground that can be reached.
To be tough and powerful, Lorna does not need to be performing black belt moves and swearing like a sailor as you suggest. She just needs to be allowed to speak her own mind, stand her ground, be shown knowing how to actually use her powers and use them to be a force of reckoning all her own. That's not "writing them out of character," that's giving enough of a damn about good writing to actually develop the characters rather than reducing them to decades old bland stereotypes.
Oh, and it's possible to have a character written better, showing themselves as tough and more powerful, while maintaining some vulnerability. Most characters have that. Without it, you can't relate to the character and they become bland to read. Lorna does not require being dumbed down as nothing but a cliche damsel in distress for the rest of her existence as a character in order to display vulnerability.