Australian Working visas with Dual British/Irish Nationality

Myself and my girlfried are looking to go to australia for a year to work and eventually get sponsored by a company but she has already used he 1 year working visa on her irish passport. Seeing as she has a British Passport aswell can she get another working visa?

Any replies would be greatly appreciated

I'm certain Australia has a one working holiday per person rather than one per nationality rule, with the exception of the second working holiday scheme for those who have worked in the primary industries.

You will sign something on the working holiday application form stating that, unless you happen to qualify for a second working holiday visa (i.e. the rules are along the lines of having worked in the agriculture industry or something for 3 months), that you haven't entered as a working holiday maker on a passport of any country:

"I have not previously entered Australia as the holder of a Working
Holiday visa on a passport of any country;"

I'd not be surprised if she applied on the british passport, she'd be turned around at the border, if she got the visa in the first place. They've publicised this very thing happening before with dual nationals trying to get a second working holiday visa they are not entitled to.