Actually Judicial Discretion permits a judge to express their opinion about how a child is being raised (including dress, language, activities, school, friends, bedtime) especially when a parent is seeking custody.
I don’t know what other reasons the judge may have had, if any. BUT, if a judge decided that allowing a 12 year old to come to court dressed for the beach is bad parenting, the judge is within her rights.
Rest assured that before the judge left her chambers to sit on the bench she had access to the full parenting report from the court/family relations social worker and school records, etc.