Financial requirements for partner visa

Hi, I am an Australian and looking to move to ROI with my de facto partner, who is an Irish citizen. We're a bit confused about the financial requirements! I remember reading that a family member, who is also an Irish citizen, could sign for you, I guess to say that they could support you if need be, instead of the state. However I haven't been able to find that information again! Sorry if I'm just being daft, as this sounds too good to be true, but does anyone know anything about this option? We're currently living in Australia; I earn enough but my partner does not. Any advice would be appreciated!