Some of this also probably depends on whether or not the King himself is an actual badass. Like, regardless of whether or not he has his army with him, what if he has some kind of Royal Bloodline magic or whatever too? Or enchanted armor, weaponry, etc? If he's intended to be a final boss in some fashion, even if he was caught alone or off guard he probably couldn't die at this point for more legit reasons besides just plot armor--we're probably not "strong enough" yet to take him down, like Link never is even after getting the first 3 McGuffins of every first half of every game.

It's still a totally in-character decision for Nadi to make, but if Telma were to present all these reasons to her in Product's next post I doubt she'd actually be convinced. It might be better for Telma to lead all that "gimme action!" fire in a different direction--maybe request that she create a distraction in the town square, or that she make her way to the top of the city wall and give a signal when the King's army is getting close. Heck, maybe go steal some other item--like say, an old signet ring from the Royal Tombs--that the King might try to use as either justification for his own continued rule, or falsified evidence against the Queen, etc.