My sister got an email from booking.com about room reservation which she never did.

Salam, my sister just got an email from booking.com about a hotel room booking under her name and email.

The problem is, she doesn't have an account on booking.com nor she did any booking (she is a responsible kid and even ask me 100 times before ordering anything or putting her info online). At first I thought it would be a scam email with slightly different email address (you know how the refund scam with lookalike emails) but to my surprise it was real email address from booking.com.

I contacted the hotel about the booking and the guy said that he will call me after checking (didn't got the call yet). Now my question is how on earth can a room be booked under an email which is not registered on the platform. Is there anything I need to worry about?