Brainard- NY orphaned 1920

Looking for help in tracing roots. I started a couple months ago but it is difficult since my grandmother was orphaned at a young age, her name is Grace Lillian (Brainard) French born Dec.,22 or 23 1920 in White Plains NY. She had 8 siblings. She is still alive but old age is taking over her memory. Her siblings names were John, Wilber, George, Marie, Ethyl the other 3 she can't remember. Now I know that there is a trace of Blackfoot Indian tribe from her side of the family. I would appreciate any information concerning her family line.