Aery sized up the situation. The guard was watching them... no, he'd started walking quickly in their direction. He opened his mouth, probably to call out and arrest them, and Aery, after carefully calculating trajectory and impact time, took three running steps and jumped, swinging her arm around the guard's throat and tackling him to the ground. She wasn't very big, but the guard hadn't been braced against her impact, and she'd gotten moving pretty fast in those three steps. While the man was still winded (for he'd hit the ground hard) Aery yanked a needle out of her belt pouch and plunged it into the side of his neck. His eyes went dark immediately. "Good night." She whispered.
But then she had a slight problem. The guards on the rooftops had heard the commotion and spotted them. One of them brought a loaded crossbow up even as the other raised an alarm trumpet to his mouth. After a millisecond's deliberation Aery grabbed one of her throwing disks ((think a miniature frisbee with a razor's edge)) and threw it at the guard with the crossbow. It cut the side of his neck in a glancing blow, severing the jugular and killing the guard within seconds. Then she spun 180 degrees and threw her second disk at the trumpet guard. That one remained imbedded in the guard's throat even as he fell to the cobbled street.
Turning back to Celaena, she just barely caught a glimpse of the pickpocket. A boy of about ten, one of the leaders of a pickpocket gang she often gave food to. She hadn't seen him around recently; apparently, he hadn't had good fortune.
"Eya, Tazz! Don' you go annoyin' my lady!" She grabbed his wrist. He was taller than she was, despite being a scrawny street boy.
"Aery? Wha' you doin' wiv one a' the purty types?! Yer not... Royalty, are ya?!" He tugged on her grip, but only gently.
"I'm no more royal than you are, Tazz! It don' matter why I'm wiv a lady, jus', don' take her coin! She's not a forgivin' one!" She let go of Tazz's wrist, slapped his hand away from her purse, then opened it and counted out twenty-five copper coins, which she tied up in a spare handkerchief and handed to him.
"I'll have more for you t'morrow. What're you thinkin', tryin' to steal a lady's purse? The shopkeepers, they'd see a grubby urchin wiv' a purse o' gold, an' they'd know you stealed it! An' then it's the prison for ya if yer lucky, an' more'n likely life in the mines or in the lumberyard! Now scat, an' don' you go tellin' everyone who I'm keepin' company with lately, ya hear me?" She shoved him lightly, and the boy thankfully took the hint and ran.
She turned back to Celaena. "My apologies, Lady Celaena. I try to better their mannerisms, only, they only even try to work at it when they know I'm around, and the rest of the time they forget everything I've taught them. He's a nice lad, takes care of a group of a dozen younger than seven, just him. They're always hungry, because they can't fight for food, except what they can steal from the average folk. He's fast enough to do well on his own, but he takes care of all the little ones. They call him "Papa" and act like a little family, the older ones looking out for the younger ones, and all trusting him to take care of them. I don't know why he does it, but he doesn't hurt them or beat on them, or sell them to slavers or brothels, so I help him however I can."