The first thing I thought of was Tim Tam's too.

The key idea is a great one and how about a pretty keyring to put it on?

A small stuffed koala or kangaroo?

Australian music?

A book written by an Australian author?

A couple of trashy magazines?

Suncream?

A pair of cute thongs?

That's all I can think of at the moment. Sounds like you are going to have a great time when she gets here.