This is the most common vocabulary referring to family members:

pai = father

nai = mother

fillo = son

filla = daughter

avó = grandfather

avoa = grandmother

bisavó = great-grandfather

bisavoa = great-grandmother

tío = uncle

tía = aunt

curmán = cousin (male)

curmá = cousin (female)

cuñado = brother-in-law

cuñada = sister-in-law

sogro = father-in-law

sogra = mother-in-law

xenro = son-in-law

nora = daughter-in-law

home/marido = husband

muller = wife

sobriño = nephew

sobriña = niece

neto = grandson

neta = granddaughter

irmán = brother

irmá = sister