Green’s Dictionary of Slang

(N.Z.) tiny, little; thus a nickname for a small boy or short person.

1917		V.C. Fussell Letter from Private Tikitamu [Written mainly in ‘pidgin Maori’] Nookie. nook man.
1978		G. Tucker Thoroughbreds Are My Life 6: Len’s nickname [...] was ‘Nookie’, which today bears a totally, different connotation to that which it did in those years [i.e. 1930s].
2010		Mail & Guardian (Johannesburg) 23 Mar. 🌐 Ag shame, poor girl. Imagine having to be his nookie koeki.