Wife second or subsequent visa?

Guys

I would appreciate your help and guidance please.

1. I came to NZ on work visa in 2003 and Got PR and got Citizenship in 2006
2. Got married and brought my wife over and have her PR visa with Returning resident visa in 2006
3. We went to UK in 2008 on HSMP
4. I came back to NZ in 2013
5. My wife is still in UK and now come to NZ to join me again.

My question is..

Since her returning resident visa was expired in Nov- 2008 after she started living in UK, so since then there is no active visa on her passort, all she has Permanent residence visa (Indefinite) on her passport.

Please advise which form she needs to fill in? and is there any complications I need to aware..

Thanks in advance.