Brook's great-grandma from brook gets grounded
Adrianna Seanrick (born November 10, 1918, died March 10. 1998) is the founder of the Seanrick family. She is also the mother of Courtney Seanrick, the grandmother of Becky Seanrick, Jerry Dawson and Arnold Jopkins, and the great-grandmother of Brook Seanrick.

Not much is known about her since she is deceased,  According to Becky's, Arnold's and Brook's memories, Adrianna died after Arnold became a teen.