Louise Creighton, Life and Letters of Thomas Hodgkin
(London: Longmans, Green, and Co., 1917), pp. 107-108:
When the proofs first began to come in, his daughter Violet, then only ten years old, found him reading them with her mother and begged to be allowed to help. He told her, smiling, that she was not quite old enough yet but should help with the next volumes. When she entreated to be at least allowed to look over and know what it was all about, he told her the story of Alaric and Stilicho so clearly that her childish mind seemed to see it all. Following on the printed page she noticed some confusion in the names which did not seem to fit with what he had told her and pointed it out. He stopped, looked for a minute, and then said, 'Magnificent child! What sharp eyes she has! That mistake would have given me many bad half-hours when the reviews began.' Ever after, she was allowed to read every proof with him. He did not in early days wish her to see his manuscript before it went to press, but wanted her to come to it with a fresh eye when it was in print, that he might discover how what he had written would strike one who did not know the period before. As time went on she was made specially responsible for technical mistakes, misprints, dates, and such matters as the uniform use of capital letters. Though she [sic, read he?] was proof reader in chief, he never liked to pass a proof without her. It was also a case of the more the merrier. Sometimes there were proof-reading parties with parents, children, governess and visitors all taking part, and it became a kind of game in which the crude suggestions of the young ones always received polite consideration.
Hat tip: Ian Jackson.