After speaking with Art, Samantha and he agreed on the following background between them while she was still in Chargen:
A couple months back Art and a couple gang members of his motorcycle club were in a blight hangout waiting for some other members of his 'club' to arrive so they could all join up and go for a ride somewhere important. While waiting he were just chilling out with his bro's and a big gunfight erupts outside on the street. A rival "club" had been chasing his buds and laid into them with guns when they were just about to Art's position.
While Art's club members filed out into the street to retaliate a gun battle ensues and during the heat of the battle few realize that this human female is moving slowly from one of Art's gangers that was shot while they were all inside.. to the next. She's using obvious healing magic on the shot up guys as green magical light flows from her hands into the bodies of his friends/club members. Art's club ends up loosing two guys, but the rival 'club' looses a good five. The general concensus though is that if Samantha hadn't been on scene Art's 'club' would have lost a good seven guys that night.
Samantha introduces herself as Sammy, refuses to accept any payment for helping your 'club' and healing the men.. though surely you and your club members will recoginize her and remember her services in the future.