Robyn...I have been in touch with WTC and have photo's of the graves, and the info that Mary Jane and Ellen (daughters) are buried with the parents... so thanks for your thought there...
I am coming to the conclusion that George and Leslie Nelson are either adopted or Illigitimate children, as Mary (mother) would have been 51 at the time of their "supposed" births...not impossible ..but doubtful...
I also looked at that site you gave me on SA BDM's online..and there are quite a few George Nelsons born around the time, so, makes it hard to check all with certificates of proof... though I have sent off for one, as advised...waiting for that reply.....
I have found through Ancestry, James Nelsons greatgrandaughter, like me, the daughter of my grans brother, Leslie...who I have been in contact, who..lives not far from me...wonder of wonders..and she does not know anything of this family unfortunately, and is very interested to find out.