TIPS TO HELP MY BEST FRIEND GET OVER HER EX !?

we’re 16 and in high school. so my best friend is talking to a guy right now and he asked her today to be his girlfriend and she said yes. but the thing is that she’s still hung up on her ex. he talks shit about her too but she still loves him. and she found out today that he lost his virginity to his new girl. WHAT CAN I DO TO HELP HER MOVE ON FULLY? i think it’s so unfair to the new guy who likes her a lot if she’s still in her feelings about her ex.