Should I tell them?

Hello everyone,

I'm needing advice on a situation and I think I know what I should do, but I want a second opinion.

So I have a new best friend, her and I have been friends online for years and met six months ago. We got connected through mutual friends who we know in real life, but due to circumstances we finally met in person six months ago though we live relatively close to each other.

My best friend has an older brother who she kicked out of the house due to him doing hard drugs and refusing to get a job to help her pay rent. Her mom wasn't working at the time, so my friend was the sole provider for the household and felt that the only way to help her brother was through tough love and she didn't want him doing hard drugs in the house and he was causing problems. He is going to rehab right now for the drugs, though he still smokes weed, and he got a job. My friend is choosing for now to love him from afar and see's how he is doing from time to time by phone or email I think.

Well just recently while I was on a chatting app called kik, it notified me that someone from my phone contacts had joined kik and I didn't recognize him. I have so many old phone numbers in my phone since I almost never delete them, so I thought that could be why this happens sometimes. So I started talking to him and I started to get this strange feeling. He told me his name and I thought that I had heard it somewhere before and his initials for his username had me feeling suspicious. Soon after noticing this, my friend started asking me about my siblings and I had forgotten her brother's name, so I asked her, and when I asked him about his initials, it hit me. The guy I had been chatting with was definitely her brother. They are both East Indian and they resembled each other. There is a 99% chance that he is using her information including her phone number to use kik since it linked to my phone number, and God knows what else he uses it for.

I'm trying to figure out if I should tell her or stay out of it. I feel like I should stay out of their business, in fear that it could make their relationship worse, worsen his struggle with drugs or wreck our friendship. I also feel that if I don't tell her that I'm keeping a secret from my new best friend and that her identity information including possibly her financial information are at risk which is the last thing she needs, because she is at risk of being homeless. I'm also afraid that if I do tell her, that her brother might find out that it was me who told her about it, and since this is a family matter this could also wreck our friendship. Which a part of me feels like who cares what happens to our friendship, as long as I help my friend. Thank God and thank you guys for your help. Also, please pray for my best friend, her mom, and her cat who are at risk of being homeless.

Thank God and thank you all for your help! I told her about it tonight amongst other things. She is going to be checking her bank account and credit score to make sure nothing as been effected. Please continue to pray for my friend to find a roommate or a new affordable place to live, and new job. This is so her, her mom, and her cat have and keep shelter, in Jesus Name amen! Also, please pray for her brother as well as he is on the path of finding Jesus, rehab/recovery, and bonding their family back together.