Well, if you want to get into the logic of that, she could always be a kid of a pair of Bleakers. Maybe they offed themselves, she was accepted in as an orphan, or they didn't kill themselves and she's just a Bleaker because she's always been one.
How is she failing to uphold the faction's tenets by being cheerful? Go on. I'd love to hear the logic, here. Being depressed isn't a requirement of being a Bleaker, it just tends to be a result, or a cause.
I'm pretty sure that between Faces of Sigil, Guide to Sigil and the Factol's Manifesto, it's pretty obvious that The Lady is interfering, even if she tends to do it subtly and only communicates with the Factols.
Anyway, one thing I've always never understood is how, exactly, the Mercykillers work.
I mean, after reading the Manifesto, they're described as the punishment part of Sigil. They only hunt and attack people who have been Judged as lawbreakers by the Guvners and execute people who have been captured by the Harmonium. They are not their own sort of police force.
Now! Does this mean that a proper Mercykiller only fights in self defense when there are no criminals around judged by the Guvners or such? Or is that an ideal case, and generally if the other parts of the Triad aren't around, they operate as Judge, Police and Executioner on their own?
And, for that matter, what the hell do they do outside of Sigil? Far as I can tell, they have no judgement of Evil on their OWN, they only obey the Guvners' judgements. Do they obey the local laws? Do they uphold Sigil's laws outside of Sigil? How, exactly, does it work?