Is it against the law?

 
Just before x-mas I received a call from CPS saying that they received a new call on Dec 3rd about an old case involving indirectly with my 6 year old Grand-daughter who has been living with me for almost a year. They asked if they could come a talk with me and my GD. I had asked if this could be done after the holidays since three weeks have gone by on their Dec 3rd phone call. We agreed to meet on Jan. 5th.
The old case involves a friend’s daughter who accused the step-father of sexual contact. My grand-daughter stated that this 12 year old found a box of moves (x-rated) and played one, but my grand-daughter said it was gross and went into another room. My daughter took my GD down to the police dept and CPS for the interview, and was told in their opinion my GD was not affected and that was that.
 In late Jan 2010  I received my GD into my care due to an unrelated issue with my daughter. April of 2010 CPS sent my friend a letter closing the case and asked if my GD can start going to church with them again. I asked for a copy of the letter and just stuck it into the file. But I did tell her even though the case was closed, I do not want my GD unsupervised at anytime with either step-father or her daughter, due to my situation.
 Dec 28th, the current caseworker came to the house for her monthly visit. She asked to see my GD room. Then asked if she could talk to my GD. My GD is accustom to people and different agencies coming over and said sure and ran to the table. The current case worker said she would like to talk with my GD in her bedroom alone. When I questioned that for the past 11 months all conversations have taken place at the table, this current caseworker informed me that she was there to visit the children and it is procedure to speak to the children alone. That we can talk on the phone whenever we want. She took my GD back into the bedroom and closed the door. The caseworker stayed to chat about anything she could think of for a while after they came out of the room, but my GD whispered into my ear asking when she was going to leave.
 After the case worker left I asked my GD what they talked about, my GD told me she asked two questions. Have I ever allowed unsupervised visits with her Mom or my friends Husband.
 I talked to the owner of the Daycare my GD and GS go to because there was a mention from the current caseworker of not ever being there, so I figured there might be a visit. During this conversation, I told the owner of the DC what happened and she informed me that what the caseworker did was against the law! Does anyone have any information on what is and what isn't policy for CPS workers?

 Note: the investigator that was supposed to come out and talk to my GD and I cancelled the Jan 5th meeting.