Blood and Honor: Sanguis is the Imperial equivalent of nobility and carries herself as such, striving to be self-possessed, well-mannered and gracious. Her fighting style is characterized by agility and grace rather than brute strength.
In Co-op Mode, Taylor ends up choosing this as a theme for her cape name, as well as playing with Medieval European Fantasy as Lady Bug. However, unlike most examples of this trope, Taylor doesn't wield the usual weapons, forgoing the usual rapier, naginata or steel fan for a steel bat. This might change in time, but as of the current chapters Taylor has stated her newfound preference for metal bats.
The canonical Lady Assassins of the Discworld have become this in the fics of A.A. Pessimal. Assassins briefly referenced in the canon have been expanded on, and OC's have joined them. While Assassins are not there to fight as conventional infantry in wars - save as a sort of Special Forces - they inescapably get involved. In Let's Bungle In The Jungle, one Assassin finds herself organising a Rorke's Drift style defence, and leading an assorted crew in a real stand-up battle. The Lady Assassins with her fight conventionally. But effectively.
Futari wa Pretty Cure Dragon has Susan Chan, who even as Cure Fortune tends to be graceful in her fighting style.
Hermione Granger and the Swiss Tournament: "Community" training routinely includes the ability to move in high society, look like a million dollars, mingle and network, recognize champagne vintages, and kill squads of heavily armed guards.
Hermione walked off the bus and into the hotel. She still had roughly twenty-five minutes before the luncheon, even after the crisis during the trial, and the attempted assassinations, and the post-trial meetings. She needed to change into something appropriate for the formal luncheon. She also needed to prep her engagement ring and reload her dart launcher. She planned to do both of those first.
Buffy from Heroes and Villains models herself on this trope fairly successfully. She greatly enjoys her various physical powers and abilities, but she is positively obsessive about her appearance at all times, and strives to project an air of elegance and cool superiority.
The Night Unfurls: Gender-Inverted for Hugh, making him more of a "Gentleman of War". He's dressed in the fancy Yharnam Hunter Set, he's an expert marksman with an elegantly designed flintlock, the weapons he usesnote they include: a cane that can transform into a whip, a katana with Blood Magic, and a curved sword that can transform into a bow are associated with grace, and his fighting style leans towards speedy finesse or "delicate" moves (e.g., blurs and flourishes) rather than "hack-and-smash" brute force. Despite being a Pollyanna at heart, he is perfectly capable of fighting in a composed, dignified way.
Kin in Teenage Jinchuriki Shinobi is far more graceful in combat than her fellow Action Girl peers Sakura and Himeko. Her movement with her knives are displayed as incredibly fluid.
The Dragon Age: Origins retelling Shadow and Rose has one of these in Elissa, the Warden, who hails from the Human Noble origin. She's behaves like a lady at all times - and has no problem kicking darkspawn ass in the same breath.
Samus: In fact, I'm not playing God. All this time... I've been playing human!note It also doubles as a Shout-Out to Superior Iron Man #3 and the DEATH BATTLE! episode Iron Man vs. Lex Luthor.
Janine from The Sanctuary Telepath is a Victorian lady - even if her actions often counted as scandalous back then, her demeanor is one of her age. She's also a graceful fighter with her long (and short) knives and a very capable telepath.
Baroness Adagio Dazzle of The Rainsverse falls under this trope. She is a member of the Heartlands' nobility, elegant, dignified, and surprisingly skilled with her Royal Rapier. And that's before she becomes one of the Knights of Harmony.
Queen Frigga is less of a warrior maiden these days, but she mentions fighting alongside one of the Sons of Bastet a few thousand years ago. She's calmly composed at almost all times, even when unleashing divine vengeance against the Red Room for kidnapping Harry.
, one Assassin finds herself organising a Rorke's Drift style defence, and leading an assorted crew in a real stand-up battle. The Lady Assassins with her fight conventionally. But effectively.