MARILYN: Very rare given name. I have not seen it before. People then used nicknames, so could be. Name spelling at that time was terrible so difference is not unusual at all. I very much suspect one and the same lady. At some point you may have to decide that this is the same person and that her husband died..also that she was a Davis. Toy could check the 1860 census and see if her husband is still alive. Then check the 1870 census and if she is still alive and her first husband not shown, look at ages and names of second husband surname. There should be an estate settlement in county records. If they moved, it will be tough.