Tessie (The Twins at St Clare's)

Tessie is a character in The Twins at St Clares and The O'Sullivan Twins. She is the head girl of the second form.

in The Twins at St Clares, Tessie hides Sooty the cat in the handwork cupboard when Miss Kennedy has to take the first and second forms together, to frighten her. The cat does its job, but Miss Kennedy considers resigning, so all the girls write a letter of apology.

In The O'Sullivan Twins, Tessie decides to give a midnight party to celebrate her birthday, and plans it with her friend Winnie Thomas. They decide to invite Pat and Isabel O'Sullivan, Janet Robins, Hetty, Susan and Nora, but Winnie cautions Tessie not to let Erica in on the secret. Erica discovers the party when Gladys takes a frying pan to the music room where they plan to have the feast, as the girls decide to fry sausages. When the girls have the party, Erica knocks on the door to scare them and knocks on Mam'zelle's door so that she comes out, smells the sausages and confronts the girls. They are sent to Miss Theobald's office and forbidden to go town for two weeks. Pat discovers from Gladys that Erica was responsible, and she is punished by the second and first form.