My grandmother's name was Mary Rovinski. She was born on May 21, 1916 and died January 12, 1995. At the time, she was living in Wilkes Barre, PA. She may have been married to a Michael. They had two children, Constance and Frank.
It is awkward to say, but there is little known about Michael. He either divorced, separated or left Mary (no one in the family talks about it). He had another relationship which may have produced other children including either your mother or father.
I never knew my grandfather. They did not like to speak about him. I know that they owned a farm (mainly growing vegetables). I was very little when he died. I believe my mother and uncle attended the funeral, though.