I searched through the Ancestry BMD Records starting from 1937 and voila! here we are in 1945

Name:Robert Waterworth
Name:Kitty Freeman
Year of Registration:1945
Quarter of Registration:July/August/ September
District:Forest of Dean
Volume:6a
Page:908

Her birth from Ancestry BMD Records which gives her mothers maiden name as Meek

Name: Kitty Freeman
Year of Registration: 1917
Quarter of Registration: Jan-Feb-Mar
Mother's Maiden Name: Meek
District: Monmouth (1837-1939)
County: Gloucestershire, Herefordshire, Monmouthshire
Volume: 11a
Page: 33