Are the faces of these victims hidden during testimony? I know the names are never released, but I'm not sure if they testify behind a cover of some kind.
In the US, sometimes the courtroom is cleared of spectators before some witnesses, though rarely and not always because it's a child. If the trial is in juvenile court (i.e. the defendant is underage), there are usually no spectators allowed. Sometimes, children are allowed to testify from a remote location vis camera so that they don't have to be in the courtroom itself. In MA, the short privacy wall that forms the box around the front of the witness stand is high enough that many kids wouldn't be visible over it anyway. In only a few of MA's courtrooms were the witnesses actually standing.
Hearings in Canadian Young Offender courts are generally public, but judges have a lot more flexibility to tailor both proceedings and penalties than they do in adult court.
I expect that courtrooms are more likely to be cleared because of the condition and circumstances of witnesses - children or otherwise - than to preserve their anonymity.