Maurice Redfern was born in 1911 father Maurice and mother Fanny.
Using the GRO index it says MMN was Key.
From FMP Maurice Redfern aged 23 married Fanny Key aged 21 a spinster in April 1911 father of Fanny was named as George Key (deceased)
1921 census Maurice Redfern was with his sister and parents Maurice (transcribed as Muriel ) and near the bottom is says was Charles William CARTWRIGHT as Father in Law.
my question is if Fanny Key was a spinster how can Charles Cartwright be Maurice's father in law or am I missing something obvious by having a senior moment?
"in-law" had a wider range of meaning in the 19th, and, it seems from this, the early 20th century. It is quite common to see step-children or step-parents described as in-laws.