Green’s Dictionary of Slang

a sixpence (2½p).

1859, 1860		Hotten Dict. of Modern Sl. etc.
1864		Press 12 Nov. n.p.: Goddess Diana is the rhyming equivalent for a tanner which signifies sixpence [F&H].
1870		Hotten Sl. Dict.
1927		Shields Dly News 2 Dec. 2/7: I gave him a ‘goddess Diana’ (tanner) and he said: Thank you for the ‘sugar and honey’ (money) .