Phyllis, Actually the 1850 Census does not state that she is "Mother in Law". By being at the end of Jame's Family we think of her as being a Mother in Law. The Census stated that she was 51 and Female, born in Virginia. She could also be Jame's Aunt or Matilda's Aunt too. I can't seem to find James in 1860 Census to see if Mary Cox is still there. Good luck on your Search!! Carolyn Whaley