Bachelorette attendees backed out after paying deposit, do we refund them

About a month ago, 3 attendees to my sister in laws bachelorette backed out after commiting and paying the deposit for the airbnb. I’ll try and keep this short and also include some screenshots that were sent to my SIL.

The bachelorette weekend is the same weekend as the one girls birthday and she wanted to celebrate just her bday with her sister and her friend (also agreed to attend the bachelorette) in another city on the Friday night (which then extended to also all of Saturday so they’d only be there for Saturday evening). 2 of them paid for 1 night deposit (instead of 2 nights) and 1 of them paid for 2 nights deposit as we didn’t know (and she didn’t tell us) she was planning to go to the birthday celebration as well. They knew upfront before paying the location, dates, cost of the airbnb and approximate cost of activities/groceries etc.

Months after committing they decide it’s too far, too much money and not enough time to make it worth it. My SIL was obviously upset about this; it’s a pretty selfish reason to cancel. They claimed they realized when we sent the itinerary but the earliest even on the Saturday was at noon. It wouldn’t have been hard to get there before that.

Do we give them their deposit back? They texting asking for it today, also accusing us of “pocketing the money” (it was already paid to airbnb). Our first reaction is no they shouldn’t get it back as with 3 less girls we would’ve booked a smaller, less expensive airbnb, we already have to adjust the final airbnb payment to account for 3 less people leaving the bridesmaids on the hook for more than agreed on (decided it wasn’t fair to charge out to others).

First 5 photos are when they cancelled (messages from the bday girl to my SIL the bride), last 2 are them requesting the money back from my SIL. One of the girls had messaged my other SIL (MOH) asking for the money and then this girl messaged the bride which was uncalled for imo! Worth noting re the uninvite from the wedding, the bday girl kept bringing up the cost of the destination wedding so my SIL said something along the lines of if it’s such a financial burden you shouldn’t come.