Can I set up family sharing when my family lives in a different country or region?

I have set up family sharing on my devices, but it seems my family is not able to accept my invitation because they are living in Australia and I am in Germany. Is there anything we can do to get around this problem? The option to share purchases was the main reason that they bought an ipad today for their 2 little sons because I have so many apps for children as I am a early childhood teacher and now it is not working . Hopefully there is a way to st up family sharing - I mean our world is global and family sharing local??? really?