It's All Relative

My mother's brother's sister's name is Grace
She's my aunt and likes to go from place to place
My mother's sister's brother's name is Brad
He's my uncle and he is my cousin's Dad

My grandmother on my mother's side
Is my maternal gran, she is my grandfather's bride
She also is my father's mother-in-law
And not surprisingly they often go to war

My cousin is the nephew of my mother
His father happens to be my mother's brother
My aunty's niece is in fact myself
I hope you're not too confused, because I can't help