I'm not sure what she's done warrants jail time. She might not have known it was wrong per se, given her educational background. Termination, definitely in order, file at Immigration, definitely. Jailing her - well I don't know if she has intentionally tried to hurt the child. Not follow an instruction yes! Out to intentionally harm/maim no!
Look from a practical viewpoint, I agree with Thanka2, you need to look inside your home and work out why this happened. It appears that your helper has to work during the day and sleep at night with your child, she needs to be able to sleep too and was just sorting out a way in which is was workable for her and may not understand the consequences. The sleeping with the child and working during the day time needs to be looked at.
MacauMum, I think your comment is a little harsh. As mums none of us are perfect but to attack the OP for asking for advice/ some perspective and telling people 'it's awful to think some children grow up with such parents.' or to imply her children should be taken away from her is unkind at the very least. Haven't you ever done something you weren't proud of when you were parenting your child, made a bad decision? Lost your temper? Who are you to judge that her parental rights should be removed? I'm hoping your post was just a very visceral reaction and that you didn't really mean it.