Laurie- My great uncle told me about the book you were discussing and I did read it. If you want family history I recommend getting it. They did have other half siblings and it covers that in the book. There is a great family tree in the book. I did go to Chan's website but unfortunately I could not afford the cost of the book. I checked on Amazon and did find a used copy for under $20 and it was well worth it! My grandmother was your grandmother's sister!