Here are two scripts can be used to create the extension attribute to check the Parental Control status on Client, take it if you need. I'm not good at coding, but they work.

1. #!/bin/sh
   find /Library/Managed Preferences/*/ -name "com.apple.familycontrols.logging.plist" > /tmp/pc.txt
   FILE=find /Library/Managed Preferences/*/ -name "com.apple.familycontrols.logging.plist" -print -quit
   if [ -f "$FILE" ]; then
   USERS=cut -d"/" -f4 /tmp/pc.txt
   echo "<result>Enabled on Users: $USERS</result>" 
   else
   echo "<result>Not Enabled</result>"
   fi

2. #!/bin/sh
   USERS=dscl . -readall /Users MCXSettings | awk -v RS="-" '{for (i=NF; i>=2; i--) if ($i ~ /RecordName:/ && $(i-1) != 0 )  print $(i+1) }'
   if [ "$USERS" ]; then
   echo "<result>Enabled on Users: $USERS</result>" 
   else
   echo "<result>Not Enabled</result>"
   fi