The 1926 birth reg shows 3 christian names - Dennis H E 
Death
Dennis Harry E Parsons 61 born   8 March 1926
Registration Date   Feb 1988
Registration district   South east Hampshire
Inferred County   Hampshire
Volume   20
Page1934
Used the 1926 dob given above for free search of the 1939 register it shows the following
Bournmouth C.B.
Dennis H Parsons 1926 Preview shows a 
Tom Parsons on this record 
plus 2 others and 2 officially closed
It appears one of the persons is
Evelyn E Holly (Parsons) 1903 
Tom Parsons and 2 more people 2 offically closed
From GRO indexes showing mmn this looks to be the birth entry of Evelyn
Evelyn Emily PARSONS 
mmn BRITTAN      1903  M Quarter in KING'S NORTON  Volume 06C  Page 496   
Evelyn married Dec 1946 Bournemouth A V Holly
Evelyn Emily HOLLY age 67 born   1 Jan 1903 died
Sep 1970 Gosport Hampshire Volume:   6b Page:   744
1911c Tom Parsons born c 1871 and family including dau Evelyn born 1903
https://www.familysearch.org/ark:/61903/1:1:XWQD-JRSTom Parsons married Alice Mary Brittan Sep 1892 Birmingham