Hiya, thanks for all the info so far! I have found the family in 1911 - Harry was born in 'C on M, Manchester', Gertrude was born in 'Horsley, Lanc' and Doreen was born 'Heaton Norris, Lancs' (at least that's what my interpretation of the writing was).
Could be them married in Kendal but they would've move in the 3 years before Doreen (possible?).