Sarah Jane Russell, Isaac Russell & Regina Hale

I've hit a brick wall... I have an Issac/Isaac Russell who might have married Regina Hale in TN(?) circa 1844. They had a daughter, name unknown, who died as an infant. They had a second daughter named Sarah Jane born 8 Dec 1846 in TN.Sarah married Wm Pinkney White on 10 March 1867 in Wayne Co MO. Isaac died abt 1856 and Regina died abt 1858 leaving 11 yr old Sarah to live with Levi Rodin, whose relationship to her is unknown. She lived with Levi until her marriage to William. I can't find any records of Isaac & Regina's marriage. I also can't find where and when they were born. Also, what was Levi to the family, an uncle, cousin, mother's fiance? If anyone out there has any info, it will be greatly appreciated.