In 1922 Mockeridge took up a post as independent lecturer in Botany in charge of the Department of Biology at the newly established University College of Swansea (now Swansea University).
At Swansea, over a period of thirty-two years, she built up the reputation of the honours degree in Botany and supervised work carried out by a succession of research students. This was achieved in circumstances that were far from ideal – with a small staff, inadequate facilities and temporary accommodation.[3]
In 1936 she was elected first professor of Botany in the College.
Shortly before she retired in 1954 her ambition to establish separate departments of Botany and Zoology with honours degrees in each was realised.[1] She also planned facilities for the new Natural Sciences Building, aware that its use would be for her successors.
Her work at Swansea extended beyond the life sciences departments. She was Dean of the Faculty of Science during 1933-35 and again during 1941-43. During the years 1949-51 she was Vice-Principal of the University College. She was also, for many years, Treasurer of the Students’ Representative Council.
In 1935, she argued the case for a pay increase for L. Thomas, Laboratory Attendant: 'He is every bit as indispensable to my Department as are the chief laboratory attendants in other science departments of the College, while his wages compare unfavourably with those of most other attendants and also with those of some other College servants, who could be replaced more readily than he could.'[4]
Beyond the university, Mockeridge was a sought after lecturer throughout South Wales. She was also, for many years, editor of the Proceedings of the Swansea Field Naturalists' Society.[3] After retiring, she became Chair of the Science Committee of the National Museum of Wales and a member of the Glantawe Hospital Management Committee.
She died on 18 December 1958 at the age of sixty-nine.
To this day, students at Swansea University compete for the Florence A Mockeridge Prize in Botany.