Action Girl/Fan Fics

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Rika and Jeri in the Tamers Forever Series.
The Femme Fatalex in the Sonic the Hedgehog story, Entropy. Members Captain Agent "Olly" Mjöllnir, Agent "Bazza" Bazooka aka Vanilla the Rabbit, and Agent Drai ner. Sonic couldn't think of a nickname for Drainer.
Pretty much every female character in That Guy with the Glasses in Space seems to fit this trope.
In true Power Rangers tradition, Maria Aparicio and Hitomi Miyazawa of Power Rangers GPX. Maria actually takes it far enough to be a true Badass.
Hermione from Harry Potter and The Methods of Rationality is one, being one of the three generals of the student armies. She's also founded an organization, S.P.H.E.W, the Society for the Promotion of Heroic Equality for Witches, to help other girls become this.
Twenty-year old Mary Jane Watson loves to keep up with the latest fashion trends, is a Twilight junkie and enjoys being the centre of male attention at parties. She's also won dozens of fights as a costumed superheroine, with a Rogues Gallery as long as her arm.
Charlie Duncan of Sapphire Eleanor Rose Suzette De Mont vs. Canon. She's part of a team dedicated to exterminating MarySues, and serves as The Big Guy of her force, carrying guns, being to first to attack, and admitting to just wanting to kill something.
In Pokémon Mystery Dungeon Journal, we have Kim, easily the most competent member of Team JUMP.
Shiki's best friend, Eri, in The World Ends With You fanfic, Eri's Game upon becoming an activist.
Cagalli Yamato in Gundam Seed Bloodlines, probably even more so than her canon counterpart.
Mary Watson in A Study in Regret, notably because she's Taken a Level In Badass since her first appearance in the Sherlock Holmes canon, in which she is simply a Spirited Young Lady.
It would be easier to find female characters in For Good that aren't this trope, because the main ones are either Royals Who Actually Do Something, captains, hyper-competent sidekicks, and/or Good Looking Privates. (Not to mention that a couple of them are actually Chessmasters.)