Theodosia learned her nursing at the Radcliffe Infirmary in Oxford. She reached the grade of Sister and is seen to have been a 'Lady Nurse' in the Isle of Wight on the 1891 Census. She married firstly in Toronto in 1896 having joined Princess Christian's Army Nursing Service (Reserve) on 16th January, 1900. The Trust acquired her Boer War unmarked silver Princess Christian's Army Nursing Service Reserve badge in May 2019. She was the great granddaughter of Lord Chief Justice Denman and re-married after Charles had been killed and became Mrs H M Vandeleur of Kings Mill House, South Nutfield, Surrey.