Hi Iris,
The children attributed to Abraham & Elizabeth Mitchel on the IGI are all member submitted so you really need to check them against the parish registers if that's at all possible.
John 4/2/1759
Mary 10/8/1760James 18/7/1762
Abraham 4/10/1764
Isaac 4/10/1764 All baptised Rotherfield.
One certainty is that there was a marriage between an Abraham & Elizabeth;
Rotherfield, East Sussex, 16 Oct 1758:
Abraham MITCHELL
Elizabeth CONSTABLE, botp (B)
On Free BMD there are a couple of likely death registrations in the name of Mary Parker in Uckfield Registration district which covers Rotherfield. Both June 1842 (7 341) & (7 331)
Found this site about Rotherfield which might be of interest,
http://theweald.org/P5.asp?PId=5251Rothjane