Have you check with the historical societies in the areas where they were born, raised etc? I also think my great grandmother had Native American blood in her from a picture I have of her. My cousin who I'd not seen for a long time looked at it when my mom was alive and said: Gee, aunt Dorothy, she sure looks like she's Native American." I'd never thought of it until he said that and I just believe he is right. I have a picture I could send. Do you have any pictures? Thanks for writing, Susan