@Jennifer-and-Boris0 Did your friend use the referral link you sent him or her to create their new account with Airbnb? You can check the status of you referral here: www.airbnb.com/invite
If they did, have they hosted a qualifying reservation? A qualifying reservation for the host referral bonus must be $100USD or more excluding guest fees, Airbnb service fees and taxes, if applicable.
If all these requirements were met, your bonus should be given to you approximately after the conclusion (not the start) of the qualifying reservation.
If you did not receive the bonus, contact Airbnb: www.airbnb.com/help/contact_us (keep hitting the "my question is about something else" until you reach a support person. 🙂