Snipped because quote chains are awful.
I said I'd be impressed if you found one; I am suitably impressed. That said, after re-reading that chapter (the book is free online; On Basilisk Station. I consider it a good read, whatever else I may think of the series as it progressed) Hauptman had decided Honor was an enemy of his long before she made her threat. I'll concede it's a point where her anger gets the better of her, but I still think given the clear narrative decision that Hauptman had to be the Bad Guy for this scene that it wasn't out of proportion or reason after he'd threatened her family over it.

You're using "Mary Sue" in a
hugely different way than I am, if the only criteria is "better than her backstory suggests". You can justify
anything with a little bit of background, and I find that criteria wanting. I think a far better criteria for such judgement is to treat the character as if a fanfic main character. That is to say, what if the author hadn't written this character, and the character was instead fan fiction? Would it be justified, or would it be patently stupid?
Lady Dame Honor Stephanie Alexander-Hamilton, Steadholder Harrington, Duchess Harrington, Countess White Haven. Brilliant strategist, tactician, politician, teacher, martial artists, swordswoman, marksman, record setting sailplane pilot, telempath. Began her career by being so good she got the home fleet admiral pissed off at her for killing him in an exercise (this is literally on the back cover of the first book). Banished to the boonies, where she uncovered and stopped a secret evil Haven attempt to subvert the system. Next, she uncovered and stopped another secret evil Haven plot to subvert another system. Then, she decisively crushed the first evil Haven attack against her home country. After that, the best duelist in the kingdom killed her lover, so she out-dueled him and got revenge. Disgraced, she was given command of a squadron of armed freighters and uncovered and stopped a secret evil Haven plot to subvert a series of systems. She ended up next in her adoptive country, where she is also a major political figure, and uncovered and stopped a secret evil domestic plot to subvert the system, and then decisively crushed the evil Haven attack against her adoptive country. Then she gets captured, oh no! But it's okay, she engineers the largest prison break ever and decisively crushes the evil Haven counter-attack, then escapes back to her home country where she gets more medals and titles. She was injured, but that doesn't matter because she got awesome new cybernetic parts that are better than the old ones. Along the way she discovers she can read emotions, so no one can ever lie to her again without her knowing.
The quality of the prose might be there, book to book, but the quality of the character is not. She is the best at whatever she chooses to do, reinforced by how everyone who could even be arguably better than her dies when it's her turn to come up (with the singular exception of SGM Babcock). Her setbacks are never her fault (there might be a few, scattered across 14+ books), and when they're more than merely inconvenient they end up being blessings in disguise that further catapult her career and skills to preposterous heights.
Contrast to Rey. No titles, no medals. Grew up on a desert planet abandoned by her parent(s), scavenged parts and machinery in order to survive. Encounters Finn and BB-8, hops into the Falcon's pilot seat, and proceeds to
scrape it across the desert floor for five minutes (

) before she pulls a maneuver that would have gotten them all killed if Finn hadn't been Johnny-on-the-Spot with the turret. They escape and Rey fixes a mechanical problem on the Falcon, but are picked up by Han Solo, who is immediately confronted by hostile gangs. Rey immediately ****s everything up and nearly gets them all killed. Fifteen minutes later, she wanders where she's not supposed to, and is frightened by spectral visions after touching Luke's lightsaber. She flees the premises, and is captured with contemptuous ease by Kylo Ren when the First Order arrives. She manages to resist Ren's force assisted interrogation, and we learn she's strong in the force (no one is surprised). She mind-tricks one Stromtrooper (and nearly fails that, too) and escapes. Later, after Ren has already been shot and stabbed on separate occasions in the last ten minutes, she picks up the lightsaber and fights him. She sucks at it. When he pushes her up against a cliff she calls on the force and dispatches Ren.
Granted, the exact source of Rey's strength in the force has not been explained, but neither do I think it needed to be in this movie. Rey gets by in the entire movie by being
just lucky enough and
just skilled enough to not die. It's not like she's pulling off impossible maneuvers in the Falcon, then landing to waltz down the ramp and gun down a dozen stormtroopers and beat Ren's ass in a lightsaber duel.