My mothers son:
Mein Burder - my brother.
My dads dad:
Mein Großvater - my gramps.
My mothers and fathers kids:
Meine Geschwister - my siblings.
Mother and father:
Meine Eltern - my parents.
My cousins sister:
Kusine - cousin.
Answers:
2.
1.
4.
2.
1.
Hope it helped,
BioTeacher101