Green’s Dictionary of Slang

joy of my life n.

[rhy. sl.]

one’s wife.

[UK](con. 1900s) F. Richards Old Soldier Sahib (1965) 41: A good deal of rhyming slang was used in those days [...] the wife was ‘joy-of-my-life.’.
[UK]J. Franklyn Dict. of Rhy. Sl.
[UK]Dodson & Saczek Dict. of Cockney Rhy. Sl.
[UK]R. Puxley Fresh Rabbit.
[UK]B. Kirkpatrick Wicked Cockney Rhy. Sl.