A black 9-year-old girl.
"told that the speech hadn´t..." I prefer "told that the speech was totally spontaneous, children don´t lie as far as their feelings are concerned. It was done by her free choice and volition.
To say that it had not been planned may (or may not) have the opposite effect, that of people being led to think that it was...or that it wasn´t planned, but somehow she (the girl) did that because she was influenced at home.
Anyway it´s me here, others may have other thinking, of course.