Joanna Elisabeth of Holstein-Gottorp

Catherine's mother arrives at the Russian court trailing her own vanity and appetites, more interested in flattery, drink, and status than in her daughter's unhappiness. She dispenses brittle advice about marriage and men, flirts shamelessly, and treats Catherine's crisis as an inconvenience to her own comfort and reputation.

Gillian Anderson plays selfishness as pure comic confidence, never apologizing for it, which makes Joanna Elisabeth hilarious rather than merely awful. The show hands her arch, self-satisfied dialogue and Anderson delivers it with a purring cruelty that exposes exactly how little a mother's love can weigh against her own vanity.