Here is how to say family members in Spanish.
Madre - Mother
(You can also say Mamá-Mom)
Padre - Father
(You can also say Papá-Dad
Don't confuse with papa-potato)
Padrastro - stepfather
Madrastra - stepmother
Los padres - the parents
Los padrastros - the stepparents
Esposo - husband
Esposa - wife
Hermano/s - brother/siblings or boy siblings
Hermanastro - stepbrother
Medio hermano - half brother
Hermana/s - sister/girl siblings
Hermanastra - stepsister
Media hermana - half sister
Hijo - Son
Hijastro - stepson
Hija - Daughter
Hijastra - stepdaughter
Los parientes - the relatives
Tía - Aunt
Tío - Uncle
Primo - Cousin
Sobrino - nephew
Sobrina - niece
Abuelo - Grandpa
Abuela - Grandma
Nieta/s - Granddaughter/s
Nieto/s - Grandson/s
Suegro - father in law
Suegra - mother in law
Yerno - son in law
Nuera - daughter in law
Cuñado - brother in law
Cuñada - sister in law