Ada Mary a'Beckett was born in Norwood, Adelaide on 18 May 1872. She was educated at the Advanced School for Girls in Adelaide.

Between 1893 and 1900 Ada worked as a teacher at several different girls schools in the Melbourne and Geelong area as well as at the Working Men's College. During part of this time she was also a student at the University of Melbourne, where she was awarded the Wyselaskie scholarship in natural science (biology) and the final honours scholarship in biology. She was Annie Grice Scholar in 1892-1893 and a founder of the Victorian Women Graduates' Association. She graduated with a BSc (1895) and a MSc (1897).

Ada maintained strong ties with Melbourne University throughout her life, working there for varying periods as a demonstrator and lecturer in biology - especially during World War I. From 1912 until 1920 she also worked as teacher at the Church of England Girls' Grammar School in Melbourne. In 1921 Ada was appointed head of the biology department at Scotch College, a position she held until 1937. She had a significant impact on her students, many of whom entered medicine or allied professions.

Ada's involvement in the kindergarten movement began in 1908 when she was elected a foundation president of the Free Kindergarten Union of Victoria. In 1916 Ada helped establish the Kindergarten Training College in Kew. Between 1920 and 1923 she helped develop the training course there for kindergarten teachers and lectured in physiology and hygiene. Ada was also the resident of the Free Kindergarten Union of Victoria from 1919 to 1939; and the president of the Kindergarten Training Council from 1926 to 1939. In 1936 she founded the Australian Association for Pre-School Child Development.

In 1935 Ada was appointed as a Commander of the Order of the British Empire (CBE) for her philanthropic work and in 1942 had a kindergarten at Fisherman's Bend named after her. She died of cancer in Melbourne in 1948.