I've known her since she was 'a babe in arms'. [=a baby who is carried in the arms of an adult; an infant]
When I began my political career, I was a mere 'babe in the woods'.
Hey 'babe', how've you been?
(..) Oh limed soul, that struggling to be free an more engaged Help, angels, make assay. Bow, stubborn knees And heart with strings of steel, be soft as sinews of the new-born babe All may be well Now might I do it, now he is praying And now I'll do it, and so he goes to heaven (..)2015 Hamlet