Tier 5 (YMS) Visa > spouse/dependant of Work Permit Holde

I am an Australian here under a Tier 5 YMS visa, expiring in 5 months time. My girlfriend is Australian and here, sponsored under the old Work Permit scheme - she has been given Limited Leave to Remain in the UK until the end of 2014 (5 Years).

We want to stay together in the UK for another few years and plan to get married ASAP. Once we are married is it possible for me to be declared a dependant of hers, and remain in the UK as her dependant? Do I need to go back to Australia and apply for a sepearte visa?

It is impossible to find any information on any website (especially UK gioverment) as she is here under an old scheme (now closed) - am I right in asking that the rules for that scheme apply?

Thanks for the help!!