My helper is selling stuff online through her facebook. Like women's clothes, and other stuff. I'm not too sure where she is getting her supply from. Should I talk to her? So far her work has been unaffected though.

She could be doing some online business with drop shipping? Of course I think you should talk to her because they are not allowed to sideline while having a work permit. If you decide to allow her to do it which I probably would (if it doesn't affect her current work) just remind her that she has to put your family first.