Immediate family includes:

Spouse (includes common law as well as same sex partners),
Child (includes adopted / step / grand / great grand),
Parent (includes step / grand / great grand / in-law / common law in-law),
Daughter, son, father, mother (includes legal / in-law / common law in-law),
Brother, sister (includes step / half / in-law / common law in-law),
Aunt, uncle, niece, nephew (includes those of spouse and common law spouse),
Legal guardian (with proof of judgement) and spouse of legal guardian.

All above include in-laws of same sex partner.