After experiencing multiple episodes of illness Anna Freud resigned her teaching post in 1920.
This enabled her to pursue further her growing interest in her father's work and writings.
From 1918 to 1921 and from 1924 to 1929 she was in analysis with her father.

In 1922 she presented her paper "Beating Fantasies and Daydreams" to the Vienna Psychoanalytical Society and became a member of the society.
 In 1923, she began her own psychoanalytical practice with children and by 1925 she was teaching at the Vienna Psychoanalytic Training Institute on the technique of child analysis, her approach to which she set out in her first book, An Introduction to the Technique of Child Analysis published in 1927.

From 1925 until 1934, she was the Secretary of the International Psychoanalytical Association while she continued child analysis and contributed to seminars and conferences on the subject.
In 1935, she became director of the Vienna Psychoanalytical Training Institute and the following year she published her influential study of the "ways and means by which the ego wards off depression, displeasure and anxiety", The Ego and the Mechanisms of Defence.
It became a founding work of ego psychology and established Freud's reputation as a pioneering theoretician.

Among the first children Anna Freud took into analysis were those of Dorothy Burlingham.
In 1925 Burlingham,  heiress to the Tiffany luxury jewellery retailer, had arrived in Vienna from New York with her four children and entered analysis firstly with Theodore Reik and then, with a view to training in child analysis, with Freud himself.
 Anna and Dorothy soon developed "intimate relations that closely resembled those of lesbians", though Anna "categorically denied the existence of a sexual relationship".
 After the Burlinghams moved into the same apartment block as the Freuds in 1929 she became, in effect, the children's stepparent.
After experiencing multiple episodes of illness Anna Freud resigned her teaching post in 1920. This enabled her to pursue further her growing interest in her father's work and writings. From 1918 to 1921 and from 1924 to 1929 she was in analysis with her father.
In 1922 she presented her paper "Beating Fantasies and Daydreams" to the Vienna Psychoanalytical Society and became a member of the society.  In 1923, she began her own psychoanalytical practice with children and by 1925 she was teaching at the Vienna Psychoanalytic Training Institute on the technique of child analysis, her approach to which she set out in her first book, An Introduction to the Technique of Child Analysis published in 1927.
From 1925 until 1934, she was the Secretary of the International Psychoanalytical Association while she continued child analysis and contributed to seminars and conferences on the subject. In 1935, she became director of the Vienna Psychoanalytical Training Institute and the following year she published her influential study of the "ways and means by which the ego wards off depression, displeasure and anxiety", The Ego and the Mechanisms of Defence. It became a founding work of ego psychology and established Freud's reputation as a pioneering theoretician.
Among the first children Anna Freud took into analysis were those of Dorothy Burlingham. In 1925 Burlingham,  heiress to the Tiffany luxury jewellery retailer, had arrived in Vienna from New York with her four children and entered analysis firstly with Theodore Reik and then, with a view to training in child analysis, with Freud himself.  Anna and Dorothy soon developed "intimate relations that closely resembled those of lesbians", though Anna "categorically denied the existence of a sexual relationship".  After the Burlinghams moved into the same apartment block as the Freuds in 1929 she became, in effect, the children's stepparent.
Anna Freud