Who is Aunta Ada Doom from Cold Comfort Farm and what is their importance?

Aunt Ada is the Starkadder matriarch. She is firm, strict, and rules with an iron fist, using allowances and claiming she's mad in order to get people to do her bidding. Ada only leaves her room twice a year.... at least until she meets Flora, as Flora's influence not only gets her out of the house, it convinces her to travel to Paris.