You need to specify details what happened ..

Picture you were the lady at HR, and someone stepped in reporting being beaten by a co-worker. What would be your first reaction?

"What happened? Why did she do it? Did you over-react? Can we resolve this quietly without getting the situation out of hand?" Those are very normal reaction.

所以楼下叫你别多说很耽误事，HR什么都不知道怎么介入？你的目的不是打击你的同事，而是解决问题。你应该讲述你理解的事情起因，她有敌意，或者她情绪不稳，以前是否有类似情况 ... 如果和她当面谈你不comfortable，你也应该直接说。你更多的是询问这种情况你该怎么处理，而不是简单"找老师告状，要老师主持公道" ...