Why won't Airdrop work for me?

I can send a photo on airdrop to everyone else (including contancts), and I've tried both options. Yet, I still can't sent it to this person who's family and they can't get mine because they don't show up on Airdrop. We tried almost everything, and it's weird because I sent airdrop photos to everyone on my bus, and then at home, I can't airdrop anyone inside my house even if they're a few inches away from me. My phone won't pick up theirs but their phone can pick up my phone, so they can only send airdrop to me. All the options are adjusted and everything's right.
… Just I can't send airdrop to this family member. They have iPhone! They have iOS 11, too, just like me. I have the iPhone and iOS 11. However, what is wrong with my airdrop?

I had this same problem, go to settings - airdrop- everyone. Just Incase your phones are not picking up that each of you are contacts. Also you can try deleting her contact and re adding it, and the last option is to reset your phones. I've always had problems with airdrop as well? Also try resetting Bluetooth. If that doesn't work call apple suport it's free.