Hi @lovemykids - in addition to the information @papinian said which is correct, I am actually an Australian on the Tier 5 visa myself. If they don't have Anchestry benefits this Visa is great and really a simple process to get, as long as they are under 30 years old :)

Tier 5 (Youth Mobility Scheme) visa. Details here: https://www.gov.uk/tier-5-youth-mobility/overview

However, if prospective au pair has a U.K. grandparent then Ancestry visa is a better alternative: https://www.gov.uk/ancestry-visa/overview

It's also worth thinking whether the prospective au pair may be eligible for passport from another EU country, e.g. Ireland, Italy or Greece. If so, it may be easier to get that passport and rely on EU free movement rights.

We are getting a young family member from Australia to come over here as an aupair for our family.

I am wondering what visa does she require to come over here? The duration of stay will be for around 6 months. Does she need a return ticket as well?

I hope there is someone here who has similar experience with an aupair comong from Australia?