Looking at the 1881 census for Robert and Sarah, it states she was (Paralysed)

1881 Census, Cirencester

8 Sm..... ? Road Cottage

Robert SAUNDERS - 77 Retired Gardener, Glos. Baunton
Sarah SAUNDERS - 75 wife - born Glos. Easington (Paralysed)
Martha ADAMS - (daughter) Widow - 35, Dressmaker- born Cirencester
Frederick ADAMS - Grandson, 10 - Scholar, born Stroud
William A ADAMS (Grandson) -, age 15, Porter, born Cirencester
Mary Ann ADAMS (daughter) - 37, Quarryman's wife - born Cirencester
John Henry ADAMS - G/S - age 3 - born Ampney Crucis
Charles Ernest ADAMS - G/S - age 1 - ditto