Is Johanna "Jannetje" van Eck, SM actually called Jannetjie in any documents? In all the ones I can see she's called Johanna. Does she come to be known by a diminutive of her husband -Jan Steenkamp, SV/PROG first name?
But isn't that a bit strange when her step daughter is baptised Jannetjie too? Jannetje (Johanna) Anna Nieuwoudt
(Maybe it was a way for the little girl to identify Johanna as her 'namesake' mother?)