She is the babysitter for Mrs. Brisby's children, though she is Martin's former arch-enemy and does not seem to like him much because of his impudence, and self-appointed community leader for the animals in the garden. She also used to be jealous of Brisby to an extent. She was voiced by the late Hermoine Baddeley and Doris Roberts in the sequel.
Auntie Shew is a close-minded pish-posh busybody who takes it upon herself to ensure that all the wild animals on the farm are safe, even to the point of intrusiveness. While sardonic, dry-witted, satirical , and often sarcastic and ironical, she has good intentions, wanting only to ensure the safety of her friends and neighbors, especially the meek Mrs. Brisby. She seems to be hard of hearing or simply too wrapped up in her own melodramatic air that she needs to be repeatedly told things before acknowledging them, as with Mrs. Brisby's children having to repeatedly tell her that their mother is not home and that Timmy is sick. Despite all this, she has shown to be quite brave, competent, and even athletic to some degree when she managed to stop the plow from harming Mrs. Brisby and even rescues the latter in the process.
Role in Film
Auntie Shrew is the one who shouts at all the animals to evacuate the field in order to escape the coming plow. When it threatens to destroy Mrs. Brisby's home, she jumps into the plow to sabotage the fuel injector and buy them more time. She also suggests asking the Great Owl for advice.
Auntie Shrew, Jeremy, and her voice actress Hermione Baddeley
Auntie Shrew when she appeared in The Secret of NIMH II Timmy to the Rescue