In the novel Dumb Witness, Arabella Biggs (later Biggs) was a sister of Emily Arundell. She married a professor Biggs. She was the mother of Bella Tanios.
According to Miss Peabody, Arabella was the plainest of the Arundell family, and had a face "like a scone".
When Professor Biggs came to Market Basing to give some lectures on chemistry, Arabella attended, and stayed behind to ask questions. According to Miss Peabody, Arabella must have been "getting on for forty" at the time. Professor Biggs and Arabella later married, and had quite a happy marriage.