One of her lecturers, Seán Keating, unsuccessfully attempted to stop her from creating fashion sketches during his life drawing classes.
Taking advice from the advertising manager of Arnotts in Dublin, Ronald Nesbitt, she returned to London to enrol in the British Institute of Dress Designers.
She noticed that there was no equivalent training school in Ireland, and with the help of her father, she went about establishing The Grafton Academy of Dress Designing and Millinery at 6 St Stephens Green.
Many prominent designers taught at the school, including Neillí Mulcahy, whilst others were pupils such as Ib Jorgensen.
As the only such fashion design training in Ireland for a number of years, Clotworthy was described at the academy's 70th anniversary as the "backbone of the Irish clothing trade".