@Zeineb2 It's unusual, but I can see where it might be legitimate- her sister may be young and an inexperienced traveler, may have arrived to a scam listing that doesn't exist, be feeling vulnerable in a new place where she doesn't know anyone and be scared and upset. As Linda suggests, I'd tell the Inquirer to just send her sister the link to your listing if you feel okay about that, and let her proceed to contact you. The sister obviously has an account if she got scammed at another listing, or else the Inquirer booked for her (3rd party booking, not allowed, so maybe the sis got turned away at the door), so sis would need to set up her own account.