Once you get yourselves into the child protective services system (by having a fight that attracts the attention of a neighbor), you must play by their rules. If you believe that the DCS investigator was out of line, you can speak to her supervisor, but they are checking to see if you are a child molester, sex offender or felon, to determine whether or not your daughter is in danger. You would be smart to go along, to get your case closed, and then keep peace in your family, so that you don't have this agency investigating you again.