A feature you can enable on the booking widget that would allow inquiring guests that are sharing the home with other families/groups to generate a cost estimate per family staying at the home, based on the total price generated through the booking widget.
The calculator would split the cost once the guest adds their desired dates, # of adults, contact info, etc. to the widget.
Bonus: This price can then be emailed to the other parties they are splitting with (or at the very least there's an easy "copy" button).