Here are a couple of videos from one of the debates where you can clearly hear her being prompted as she is rattling off facts. One is a C-Span video in case there are doubts it has been manipulated.
Also, in case there is any doubt again, here is a link to both of these videos as well as a pic of the exact moment the word ‘dozens’ was heard (which H promptly repeated) and Trump and HRC both had their mouths closed.
https://ibankcoin.com/flyblog/2016/10/20/was-hillarys-earpiece-audio-picked-up-by-mic-during-debate/
Thanks! Will watch later on today.