In researching my Niblack line I found that John Cockrell Niblack was supposedly married second to a Miriam Crowe.... but in looking at the 1850 census it appears that living with them are a John & Mary CREED......this couple appears to be her parents and they were both listed as being born in Virginia.
So here is yet another Crowe/Creed connection....
It seems that maybe Miriam's maiden name might have been Creed and she married a Crowe before marrying John C. Niblack.
Do you know the parents of the Mary/Matilda Niblack that you mentioned? I would love to connect her to the proper Niblack branch as it might hold a clue to this CREED/CROWE mystery.