Thanks for asking your grandfather!I'm sorry it doesn't match up with what I have, even though what I have isn't much.
My Irene Pistey gave birth to my mother in 1933 when she was 21 and unmarried.She named my mother Virginia Pistey and gave her up for adoption.Based on the information I have from the adoption agency, in 1933 Irene had four sisters who were at that time -17 years old (born in 1916?) -24 years old (born in 1909?) -26 years old (born in 1906?) -and "oldest sister" whose age was not stated but who was married and had a four year old child (born in 1929?)
My grandfather was named Stanley Strange as was said to be "of English descent."
Perhaps Irene and Stanley went on to marry and have more children.Perhaps they never saw each other again.Perhaps Irene married someone else or perhaps she never married.I have no idea.
I would love to find out more about this puzzle.I really appreciate the effort you are putting in!