Pretty sure it's the same here, she can't just decide on her own (no parent can) that the other parent is not going to be allowed their time with the child, if they do then it's most likely contempt of court.
To the OP... Obviously you know you need to talk with your lawyer, I would suggest setting up a meeting in your house with your child, your lawyer and DCS (NOT the ex) and you try to keep back as much as possible so that the people from DCS can see your childs true feelings about the snakes without your influence.