@Diana213
Everyone else is correct Diana, if she cancels the booking now she will be penalised, and penalised far more severely than just the dollars difference between her off and her peak! She is just going to have to accept that she was not 'on the ball' where this one is concerned and the best way out of this is to just accept the lesser amount, welcome the guest when the time comes and do it in good grace, because this is not the guests fault....it is your mums, so don't penalise the guest.
You say it's a bit harsh Dianna! You must remember there are over 800,000 Airbnb hosts around the world and if Airbnb simply gave in to every mistake that happened on the part of those hosts every day, the platform would be in total chaos.....nobody, guests or hosts, would know where they stood. Rules are rules for a reason....and 'oops' is not a way around them!!
And you should not really bring age into it...in-experience maybe, but not age......I am 72 and there is no way I would make a mistake like that. Live and learn Diana and your mum will have a good hosting career!
Cheers.....Rob