13 year old sister pregnant????????????? ?!

WOW this is a tough one. How old are you? Do you and your sister have a very good relationship? How did she react when you asked her about the pregnancy kit Was she sad that you found it? Was she open with you? On one hand I would say try talking to her again. Tell her you love her and understand she made a mistake but in order to get the help she needs, she will have to tell your parents. Tell her if she doesn't then you may have to, but be calm and nice when talking to her as she is probably scared and nervous etc. Don't sound mad or upset and tell her you love her and want to help. Tell her you will be there in the room with her if she wants when she talks to your parents just to give her moral support. Give her a day or so and if she doesn't tell your parents then tell her you will have too.
On the other hand, instead of just talking to her you may want to tell your parents because of the situation. BUT I DON'T THINK YOU SHOULD TELL THEM BECAUSE SHE ASKED YOU NOT TO AND IF YOU DO THEN SHE MAY GET MAD AT YOU AND RUIN THE GOOD RELATIONSHIP SHE HAS WITH YOU. HOWEVER, she should tell your parents.

Your parents have a right to know about something like that if she is only 13. It's also probably best for her that they know whether she thinks that or not. She is unfit to have or care for a child at her age and appropriate actions need to be taken.

this is a serious situation your sister is in. she needs to tell her boyfriend first, then tell her parents asap.
if she doesn't soon, perhaps you should as it is a very serious situation. if she leaves it too late she may not be able to abort it.

Don't tell your parents. Leave this matter to your sis, her bf, and the parents.

When they DO find out (her procrastination is only making it worse), the situation is going to get h-e-a-t-e-d, and you may not want to be involved at all.

You absolutely MUST tell you mom and dad. This is not something to play around with. Your family is going to have to have a serious time ahead.

I don't think YOU should tell your parents since it's her decision, but I think she should tell them; no matter what happens, your sister will need the support of your family in whatever decision she makes. They shouldn't deal with this alone.

Before it get worse you should tell this to your parents. Otherwise it may affect your sister both mentally and physically life long.