After leaving school, Barker attended teacher training at
Whitelands College in
Chelsea in the 1890s. She became a schoolteacher who specialised in "troubled" children, teaching classes of up to sixty children from the deprived areas of London. Her first role was as Commandant of the
Women's Legion cooking section, She was then appointed Chief Welfare Superintendent of the
Royal Arsenal,
Woolwich, overseeing 30,000 women munitions workers. Her workers were surrounded by dangerous chemicals and TNT, but Barker organised canteens, first aid provision, recreational activities and rest rooms for the women. she was appointed governor of the
Borstal Institution for Girls at the Women's Prison,
Aylesbury, which held 100 female offenders between the ages of sixteen and twenty-one. Under her administration, Barker made sweeping reforms that focused on education and rehabilitation. She worked as Governor until 1935. In 1935, Barker became the first British female assistant prison commissioner. Barker became responsible for all women's prisons in England and Wales and worked to reform women's prisons throughout England, Wales and Scotland, based on her work at
Aylesbury. She retired in 1943. == Personal life ==