@John1080
I agree there is a tendency for 'individual' cases to mushroom & diversify during discussion on CC posts.. (Perhaps it's unavoidable on a global forum?)
However, to bring it back to this particular case, I believe my primary questions are still worth contemplating: a) What was the precise wording of the mother's message to Ricky; b) How did Airbnb deal with it?
The reason I think these queries are worth articulating is because Ricky states she's not experienced, and it's part of a learning curve.
I would only add that about 4-5 years ago, prima facie, I experienced something similar, but which I initially managed to address before accepting the booking:
A woman sent an ambiguous Inquiry for 3.
I questioned who they would be?.
She then revealed it was her son and two friends, (who were musical students attending audition at Royal College of Music not far from my home).
After the booking, on arrival the 3 teenagers turned up with an additional friend... and would it be ok?
Yes, it was ok, because I could accommodate the extra one.
The mother hadn't been aware of this addition, but happily paid for the extra guest.
End of Story.
In this case, I didn't even involve Airbnb. But I don't recall if the 3rd Party Booking Rule was already in place.