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.

Personally I think that it's best for you to casually bring it up with your helper and ask her about it. I don't think it's nothing wrong for her to earn a little side income if it doesn't affect her work and it's nothing illegal. The fact that she has left her family behind to come to a foreign country and work for another family means she needs the money for it. If she gets your blessing, she will be grateful for it and work harder. However, I would suggest for you to draw the line clearly if she starts neglecting her actual work.