Thank you so much STG, the age of the female FC does fit with my ancestor. She was born Frances Ashmore in Calow near Chesterfield in May 1818. When she married my 3xGt Grandfather John Cowlishaw in May 1847 she was already a widow. For a long time I'd been puzzled by her apparent absence from the 1861 Census. John Cowlishaw died in June 1857 and the death certificate indicates that the informant was his neighbour rather than his wife which seemed strange. Their only daughter, Mary Elizabeth, born in 1848 is in the Chesterfield workhouse in the 1861 Census and yet by 1871 she is living with her mother again who has remarried (John Cutts in June 1864) and once again living in the Chesterfield area. Frances' internment in the Derby asylum between 1856 and 1863 explains a lot.