Hello

Since Ellen was born in 1845, she would not be listed with her parents in the census prior to 1870 unless her parents were free persons of color. So you are gonna have to find the slave records of Ellen and in doing so, you may find her parents. To do that, you must know who the slave holder was. It would pretty hard to do it via the census records unless there was some Brights living near her in 1870 and 1880. So, your next step is to determine who the slave holder was and once you find out who that was, you can search court records such as deeds, estate/returns records.

Good luck,

Tony