Perhaps she gave herself a middle name?

A marriage
March 1926 Scarborough 9d 592
Harrison, Edna M. - spouse Sawdon
Sawdon, Frederick - spouse Harrison
Free index to 1939 has
Edna M Sawdon, born 1902
living with Frederick Sawdon and 4 more people, 1 closed
at 41 Saint Pauls Terrace, York C.B., Yorkshire (West Riding)
First born after that marriage?
Dec 1927 Wetherby 9a 176
Sawdon, Douglas
mother Harrison
DeathOctober 1992, York
Edna May Sawdon
d-o-b 14 June 1902
That would have to be a very fast birth registration!
In that sub-district in Guisborough, June qtr 1902, there were 91 birth registrations, and Edna was the 76th.
http://www.teesvalley-indexes.co.uk/