I hope someone can help guide me

My situation is: I am a British citizen, and I have been living with my Australian girlfriend for 2 months in Sydney (met Jul-13, 14 months). We are visiting England in December and would hope that I could find a visa for her where she can remain in the UK to work or study for a year.
Looking at the Partner route of the "Apply to remain in the UK with family" Visa, it says we need to prove one of the following:
-you’re married
-you’re in a civil partnership
-you’ve been living together in a relationship for 2 years
Source: https://www.gov.uk/remain-in-uk-family/eligibility
Although we are not married and have not lived together for 2 years, we do have a Registered Relationship document in NSW Australia (New South Wales Civil Partnership Declaration). My question is: Would the UK Immigration consider this to be satisfactory evidence of a relationship/civil partnership, therefore we could apply for this Visa on landing in the UK?
Thanks in advance,
Tom
From Stockport, UK (Living in Sydney)