At their mother's knee - Idioms by The Free Dictionary
at (one's) mother's knee (redirected from at their mother's knee)
at (one's) mother's knee
From one's mother, typically when one was a child. I learned how to bake at my mother's knee when I was just a girl.
at your mother's (or father's) knee at an early age.
at your ˌmother’s ˈknee when you were very young: I learnt these songs at my mother’s knee.
References in periodicals archive
Duffy again, "for what seemed like the millionth time in my career," had encountered Belfast's code of omerta "that babes must learn at their mother's knee
MAnd many a celebrity chef puts their kitchen skills down to what they learnt at their mother's knee