If you have a bit of storage space then consider buying a couple of inexpensive easy wipe stackable chairs (eg ikea) for visiting kids to use. Parents and you can then relax and enjoy the meal without worrying about your upholstery. Alternatively, tie-on seat cushions will give some protection plus a height boost for little ones.

What sort of leather? Last time we bought a lounge suite the salesperson enthusiastically directed us to their special of the day and we thought we hadn't been looking at leather but it was a surprisingly good price. However as soon as I sat in it I was aware of a faint unpleasant smell. I don't know if smell is a reliable giveaway, or if people can reliably smell it as my husband didn't notice until I mentioned it. So we kept looking and by comparison some of their other sofas had the lovely leather smell you would expect. Only later did we learn there is significant variance in what is sold as leather and I've seen some terrible reviews. https://www.choice.com.au/home-and-living/household/furniture/articles/leather-couches

https://www.fabricmill.com/coral-reef-oceanside.html. On their site there is no mention of shipping os, they use UPS. UPS ships to Australia. I suggest emailing or ringing. I have got fabric from Fabric.com. Great service, 7 days to Qld pre-Covic. Be aware that it is usually multiples of US price for us.

after buying new fabric lounge chairs after many years with leather we are convinced that for those of us who like to snack in front of the TV there is no better option than a leather that can be easily wiped clean after a spill