Mr O'Sullivan

Mr O'Sullivan is the father of Pat and Isabel O'Sullivan. He first appears in The Twins at St Clare's.

The Twins at St Clares
Mr O'Sullivan decides to send Pat and Isabel to St Clare's School after they have been at Redroofs School for years, as he thinks that they are getting too high an opinion of themselves. He writes to Miss Theobald and secures them a place.