Welcome to rootschat, Outlook 85.
This looks like your grandparents' marriage:
Marriages March quarter 1931
Mary E McKay Westhampnett 2b 666
William J Mills Westhampnett 2b 666
You can then look for births on free bmd for children with parents Mills/McKay, probably in the Sussex area
http://www.freebmd.org.uk(Possibly 9 from 1931 to 1952)
Rootschat is not keen on discussions about living people (even with their permission)