sometimes evidence can be uncovered in a civil trial, that may not be obtained any other way, that would be significant enough to be used in bringing about criminal charges. Maybe that is why the police officer grandmom wants to make sure that avenue is left open for her - Virgie wants Stern's hide, especially after the way he's been allowed to treat her regarding the grandbaby.
and is she above reproach trying to “use” her grandchild to exact revenge? I think not.