“My mum and I can’t tab on my younger sister”

 "My mum and I can't tab on my younger sister"
From a female blog reader:

I read a lot of stories here and it makes me feel a little better about this whole drama happening to me and my family. My story goes like this. I am a 22years old girl and i have a younger sister who will be 20 by November. We are the only two females of my parents. I am a medical student in my 4th year and I study in Ghana while my sister on the other hand is a communication student who studies in Enugu. We are from a very comfortable family. This thing all started around the ending of 2014. I was in school and i got a call from home(my mum called) that my sister is pregnant.I was so confused because this is a girl that doesn’t lack anything and as at that time, she was in SS3 so how can she be so interested in Sex. I started crying and my mum was also crying on phone trying to understand where she went wrong training me and her. I decided to talk to my sister,she started crying to and saying it was a mistake and all and the boy in question isnt even her boyfriend.He was just a random person. So we had to allow her abort the pregnancy. We couldn’t tell my father because we didn’t want him to have high blood pressure. So we talked to her and gave her some advise and she promised to change.we all became so close to her and tried our best to always talk to her to keep her on track. So fast forward to july/August 2015 she started complaining that her private part scratches her.we took her to the hospital only for the doctor to tell us that she has gotten and infection(Genital wart) we were shock and the doctor said the virus takes time to develop that’s why she ddnt have the symptoms early. We had to run a test for her which was very expensive so we had no other option that to let my father know so that he can givenus the money to run the test. My father was so sad and angry.He just ddnt know what to do to her.we did all the needfull and treated her. Everyone forgot about it and we were so happy with ourselves and i went back to Ghana. Now just today,i got a call from my mum saying my sister has done it again..She went to have sex again with another man we don’t even know. As at now,we cant say if she is pregnant or has contracted any deadly virus. Help please