Green’s Dictionary of Slang

1. (Und., usu. Aus.) to follow someone who is a potential target for robbery or fraud.

1898		E.E. Morris Austral Eng. 415/2: Shepherd, v. [...] The robbers knowing he had so much coin about him, determined to shepherd him until an opportunity occurred of robbery with impunity.
1928		Truth (Brisbane) 1 Jan. 18/3: To trail a man with ultimate designs on his money — or ‘roll’ — is to ‘shepherd him’.

2. to watch over carefully, to shadow.

1873		Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 7: Shepherd - To look after carefully; surveillance.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1894		Truth (Sydney) 4 Feb. 3/7: From information received [he] decided to have her ‘sheperded’.
1900		Bulletin (Sydney) 6 Jan. 20/3: Easy enough, you fool! I always shepherd them hairy-faced blokes from the club. They can’t smoke more than half a cigar for fear of burning a hole in their moustaches.
1901		Bulletin (Sydney) 20 Jul. 15/4: Johnny, you go and find her clothes for her. I’m sick of shepherding yous kids. Where’s maw?