I wonder if George might have used the surname Gray when he married (or Jackson Gray?) - with Lily being Lily Fowell Peet b 1900 Nottingham. I think the family uses the surnames Jackson Gray in 1921
Marriages Jun 1918
Gray George H J Peet Nottingham 7b 688
Peet Lily F Gray Nottingham 7b 688
Kay
Added - I noticed a baptism for son George on 29 Aug 1920 at Sneinton with surname listed as Jackson-Gray on the image but the transcription incorrectly lists the mothers surname as Gray
If the above is OK the first four children appear to be registered with mothers maiden name Peet
GRAY, CLARICE JACKSON mmn PEET
GRO Reference: 1922 J Quarter in NOTTINGHAM Volume 07B Page 608