Pictures of Minors on Facebook without Consent?

Hi I have a minor under the age of 7 that I have legal guardianship over. Someone on Facebook has posted pictures of my child without my consent. I asked them to take the pictures down and they refused. I then filled out Facebook's form to have them removed. Facebook had the pictures removed. Then the individual reposted the pictures and deleted me from their friends list. The problem is that in order to fill out the form on Facebook to have the pictures removed again I have to have the exact URL for the pictures that I want removed. I cannot get the URL of the pictures as the person has deleted me from their friends list. Nor do I know any on their friends list that could tell me it. Yet, I know that the pictures are still there. This is very frustrating. What can I do to get these pictures removed for good? Any help would be great.