Worst. Mother. Ever.
Karen's mother treated her like some kind of baby alien. She not only tried to control everything about her, she also never gave Karen the slightest bit of respect. At least Richard respected her, but his jealousy of her was palpable because he was a run of the mill piano player, while she was a star. The father was also distant and not particularly kind. Karen was a victim of her weird family.
At least there will be plenty implied.