My first reaction is that (to use some of my former life management-speak) you should see this as an opportunity rather than a threat.
I rather doubt that any teaching staff would be looking for presentation perfection from a youngster of 14. Far from it, just the confidence to stand up and deliver 2 minutes (?) worth of rational arguement .............. and in a language that isn't her natural tongue.
They're pushing her - perhaps no bad thing for any youngster.
My only worry would be whether she has been singled out as the only one to have to do this - if that were to be the case, then I'd be much more concerned, in fact it would be totally out of order. I'd be staggered if that was the case.