ONE OF MY FRIENDS WANTS TO HAVE WITH HER BF AND THEY ARE BOTH 15!!! I NEED ADULT ADVICE!?

Okay. I have a friend named Bridget and her BF's name is Cody. I am 13 and Bridget and Cody are both 15. Bridget has her period and all that stuff but she didn't know how to have . or what happens with or anything like that! anyway she asked me to explain to her how to get pregnant and I told her all about it cause shes a 15 year old girl and should know this right? Well right after I told her I asked if she was thinkin about doin anything with her BF and she said yes now that you tell me that sounds fun. And then I told all the pain that comes with it and all that stuff and she is not telling her mom any of this. Also she can't even spell pregnant! she spells it pregnit! AAnd I dont think I can change her mind or anything. I've asked her if there was anyway I could change her mind and she said no. And I am gonna talk to my mom about it to but it is easier if I can get answers from people who I cant see and dont have to reply to. Any ways she is going through a tough time right now cause both of her parents smoke and drink and sleep around with other people and they are getting a divorce. So I need some help. Adult help. What can I say to make her change her mind? I'm really scared!