How To Ascertain That One Is A Virgin?

Hi, I am 19 years old as well as my friend, we are both virgins. Now my friend has a problem, yesterday her boyfriend persuaded her to sleep with him and she agreed but immediately when they started she realised that its painful and told her boyfriend that he does not want to continue anymore. So she is worried, I would like to ask as to what is it that she have to look for to find out that she is still a virgin or not because we used to go to these Zulu ceremonies for virgins!