LittleThumb on Family Tree Circles

I was told by my parents (both deceased now) years ago that I am a g-g-g-g-grandaughter of Sitting Bull. My mom & grandmother were both born in North Dakota....my Grandmother was born in 1896 and my mother in 1930. My grandmother was 1/2 Sioux Indian. The only information I have found is hand-written notes from my parents that Helen Lorraine Bergie's (my grandmother) parents names were Alec Bergie and Caroline Little Thumb. My search over the last year or so has exhausted me. I would like to know if anyone has any information relating to them or if there's an easy to read family tree from Sitting Bull down to current generation of descendants.