There are a few actions described here. A few of them could trigger combat. Consider it a declaration of intent. I'll edit my post if combat starts sooner than I'd like.
When the child approaches her, Rosa puts her dagger back into her belt. She crouches to make their faces level, then pushes a silver piece into his palm, before whispering to the child.
In a deadly serious, non patronizing voice: "These men using you are not your friends. One day they will turn against you, if they haven't already. If you want to live free, run down Bridge, into Market and then to the Spotted Dog. Wait for me there. I'll check on you in a couple days. Anyone gives you trouble, tell them you're under the Bloody Rose's wing. Now you better run, kiddo."
Rosa takes the paper from the kid, and as she stand up, loses it. "Oopss..." She turns to the bowmen accross the street, letting her hood fall down to show her face. Hoping your undeserved reputation will save you, girl? Even if these idiots know you, their intellect sure seems below a frog's and its self preservation instincts.
"Would you guys be gentlemen and kind enough to help a delicate Lady pick this paper up from the filth? I unfortunately didn't get the time to read what's on it? I guess not. I must say I don't like amateurs. But I especially hate people taking advantage of children."
Rosa nonchalantly pushes the flap her cloak away, showing her loaded crossbow, keeping it pointed on the ground.
"Consider this your only and last warning."
Loki bless stupid ambushers...
So, there are bowmen above Rosa, i.e. above that hoverhang under which she is standing, and also bowmen accross the street? I'm a bit confused.
Three upstairs and two accross the street? At least 5, then?
Convincing the child: Persuasion - (1d20+2).
Convincing the thugs: Intimidation - (1d20+2).