Thankyou to all posters here for continuing to give me very useful hints about where to go next with this lass.
The 1861 Census & Free BMD does indeed show that there was a younger sister, and suggests that Jane herself died in 1864. The children seem to be living with an Uncle's family by 1871. Brief & Busy lives, eh?
Not yet coming up with any details on her marriages, but as Tati said, they could have married in Ireland.
Particular thanks to dobfarm for the hints. I have now tried all combinations of V, B and L - with Mc, Mac, etc, etc.
I'm very grateful for the use of your eyes & brains. Shall we call this topic closed now, as it's becoming more about Jane than about the handwriting!??
All the best, Lisa