Hi @Jayne96 .
I see that your listings all say child free environment and / or must be 18+.
However, in your house rule descriptors, all but the first listing state Not suitable for infants or children with the house rules at the front of the listing saying not under 12. This info could be repeated at “other things to note”
Alter the wording in the house rules as specifically stating adults (18+) only only allowed to be on the property. As a matter of safety, any bookings received where guests under 18, will not be accepted.
Place the age statement as suggested by @Helen3. Also only adults allowed on site. 18 years is an adult in Australia.
Also, take it further and ensure the tabs for infants under two and over, are not switched on.