Answer :
YOU SHOULD ADVICE HER TO KEEP QUIT OTHERWISE U ALL WILL LEAVE AND SHE CAN DISCUSS ALONE.
you should give a advice her that talk very slowly & give chance to other students . u should also explain disatvanges of talking loudly. if she doesnt does that thing make your friends not to talk with her . then she will realise the mistake which done by her . and then she not talk loudly & gives the chance to other students