[1] Flagg was born in South Shields (then part of County Durham) on 30 September 1893 and lived in Westoe.
[5] At the end of Anya Seton's 1962 novel Devil Water (featuring James, the Earl of Derwentwater and his involvement with the Jacobite rising of 1715) she thanks Flagg: "My greatest debt of all is to Miss Amy C. Flagg of Westoe, South Shields, Durham, in England.
For her researchers through the years, for the masses of specialised material which she has patiently copied for me, for her constant encouragement when I've been with her, and by letter when I haven't - for all this my fervent gratitude is but sparse return".
[6] A watercolour painting of Flagg, by Albert E. Black in 1955, shows her in a long brown coat and carrying a basket of flowers and an easel; it is in the collection of Tyne and Wear Museums.
The plaque was due for installation in 2021 but was delayed by the Covid pandemic and was unveiled by the Mayor of South Tyneside on International Women's Day 8 March 2022.