barristers are very very very careful not to believe or suspect that a client is guilty. The solicitors client in the "best interests" sense would be the juvenile although depending on the age and understanding of the child, obviously the parent or guardian would be heavily involved in the process. The defence obviously build a defence. Witnesses swear to tell "the truth, the whole truth and nothing but the truth" and are not allowed to support prosecution in that respect...indeed there is such a thing as a "hostile witness" The feelings/opinions of the people who know the child and are interviewed by counsel for the defence are likely to vary aren't they?
Why do you ask?