Who is Veronika's Mother from Veronika Decides to Die and what is their importance?

Veronika's Mother remains a minor character, but in the way she submits to the manipulations of Dr. Igor, she can also be seen as a symbol of the sort of unquestioning acquiescence to rules, boundaries and authority that the narrative suggests is a powerful inhibitor of true happiness. This symbolic value is reinforced by Veronika's memories of her mother squelching Veronika's desire to play the piano professionally..... in other words as a source of a life-denying boundary.