I'm not sure if this is correct but, according to some on the SubReddit yesterday, Sam is legally old enough to work in Massachusetts, so long as Union Robotics is a properly-registered place of work (and I can't see Punchbot having skimped on the paperwork). Because of ths, so long as Jim and/or his ex-wife agree, there is no reason why Sam cannot work after-school and possibly weekends, even if only on a by-commission basis.
Naturally, if she develops a rep amongst the local Synthetics as THE hull inker, the fact that she is only available for a dozen or so hours a week will make it harder to get an appointment and, naturally, that having a Genuine Sam Bean that much more a status symbol amongst the robo-hipsters.
You do realise for that to work, Sam would need to have a great deal of maturity and attention, when currently it seems like Sam has the attention span of a ADHD rabbit that is stuck in a room full of shiny objects.
Hard cash has an almost UNCANNY ability to focus teens, though...
It's also a matter if she has ADD, ADHD, or is simply extremely enthusiastic and energetic. Money does absolutely nothing for cases like mine.
The thing with ADD and ADHD is that we (I have ADD personally) actually can have some pretty extreme focus. The problem is that it absolutely has to have immediate and apparent rewards that we feel we can achieve. If we can (or are taught to) conceptualize the idea of a long term goal, we can spend an insane amount of time on one activity. It's called Hyperfocus, and it's the kinda shit that can lead kids into burying hours in WoW or building insanely large structures in Minecraft in survival mode.
Where we tend to run into trouble is when it's a project that isn't point A to Point B. If we don't see an end in sight, we kinda tend to get bored, and try to find something else to sate our need for novelty. That's why a lot of people with ADD and ADHD have a terrible time with school, since there's such long term goals and very little external reward for accomplishing good grades. An A on a paper doesn't mean very much to me, but a completed project does. I imagine for someone like Sam, if she does have this kinda of alternative learning style, completing an art project is the reward. If the project doesn't have a definitive end goal in sight, we'll fracture our attention, drifting from project to project in hopes of finding something that DOES sate our need for competition, and before we know it we have NOTHING done.
So Sam can probably excel at this new little side job, as long as she's allowed to do what she wants, and it all gets done in the same appointment. She would of course need guidance (And maybe medication) if she wants to become a serious artist and go after long term goals. It really is about the environment you're raised into and the skills you're taught to manage the different way of thinking. I'd be curious to see how she reacts to an AI that wants a specific commission that might not suit her tastes. If there's a learning opportunity, it'll be that one.