Much doubt about her surname. The only record we have is her marriage certificate to Abraham Slack in 1687. Many in ancestry have interpreted this as Mary Coates, but this is inconsistent with the actual name written. Also, there is another Mary Coates who married someone else in Wirksworth just a few months earlier, 11 May 1686, so at a similar time, and the name there is clearly Coates. My interpretation is that the name written is actually "Samson", and there is a Mary Samson born 10 Sep 1666 at Moorgate, Retford, Notts, whose birth is registered in the Quaker archives at Mansfield. So this date would be consistent with the death certificate of Abraham's widow in 1715. The certificates come from the Quaker meeting of Derbyshire and Nottinghamshire at Mansfield, which indicated her parents were Alexander Samson and Mary, from Moorgate, near Retford, Notts.