Goodness gracious, I can't get to the website for one day and all of this!
Okay, whew... let's begin. The Knave's momento... well, given that the knave only met her in the story for a few seconds, I'm not sure he'd have been able to give her something... but, since we're taking a creative license, I'll start thinking of something. I've got an idea, just need to figure out what to do with it...
For the Tweedle Twins, he may have passed through their shop from time to time. He's an unscrupulous character at times, and not often trusted, but if he's built up a good rapport with them it could be that he consider them to be a step above from acquaintances. (He hesitates/refuses to actually call anybody a friend.)
Is there something else? Probably.