Overman's widow it is.
Here are some definitions at different dates:
Overman 1825: one who inspects the state of the mine every morning before the men go to work. He also keeps a daily account of the men's labour.
1849: The person who, beneath the viewer, has the charge of the workings of a colliery where there is no under-viewer. He sets the pit to work each morning, and attends to all the detail of arranging the work, and getting the coals each man works to the shaft bottom. It is also his duty to see that each working place is properly ventilated and in a safe state. He also keeps a daily account of the work wrought, and of the whole of the underground expenses and wages, and gives the colliery office a fortnightly account of the same, the bill containing the amount earned by each man, or set of men if in partnership, and boy during that time. There is one overman to a pit, so that if there are two or three pits at a colliery, there are two or three overmen. An overman is almost invariably a man who has passed through all the graduations of pit work, from the trapper upwards, and who has been raised to his situation on account of his ability and steadiness. His wages in 1849 were 26s. to 28s. per week, with house, garden, and coals gratis.
1892: The duties of the overman consist in visiting the workings every morning, receiving the reports from the deputies, making observations on the air currents, and general management of the underground work. To his office is sent an account of all the work done in the pit, and on the Wednesday before the "pay" he "reckons" with the men - i.e., he compares the account received of their work with that kept by themselves.
1894: Underground foreman subordinate to the manager
vv.
