My fiancé exhas taken his children from there home with us using the story that he and I killed my late husband who was not living with me but broke into my house and shot himself 2 yrs ago. It was investigated and proven that he did commit suicide. She is telling all of our family members that we killed him and using it as her excuse for taking the kids we currently have emergancy proceedings to return them to home.

Well firstly, you don't bring "charges" for slander. Slander is not a crime, it is a tort (civil action). If the claims are being made as part of a legal proceeding, they are protected as an exceeption to defamation. (ie: you can say anything you want in court without fear of a defamation suit). The big issues with a defamation suit is showing that you have been damaged and the extent to which you have been damaged.

Have you addressed this with the attorney representing you in the family court proceeding?