I've now found a marriage between a Mary Miller(mine?) and a Robert Joseph Corrin in 1873, Douglas. He marries again in 1879 so she must have died. If it is my Mary Miller, born 1837 it could explain why I couldn't find a death for Mary Miller. That said, I can't find an appropriate one for a Mary Corrin either! If it is her, Thomas Miller must have died before 1873....and where was Florence? There is a Florence Mary Ri(e)dgate of the right age in 1881working in Chorlton on Medlock, where she was born, but no sign of her mother.