Physics teacher (School Reunion)

The usual physics teacher at Deffry Vale High School was said to never have played the lottery when she won; she was given the ticket through the door at midnight. In 2007, the Tenth Doctor replaced her, unlike the other new members of staff, whose predecessors, according to Mr Parsons, had the flu three months earlier. The Doctor simply responded, "The world is very strange." (TV: School Reunion)

Behind the scenes
After her only on-screen mention in School Reunion, other Doctor Who media has given the Deffry Vale High School physics teacher several different names and accounts of her lottery win.

Victoria Mehru
According to the Deffry Vale news website, the teacher who won the lottery was 42 year-old Victoria Mehru. Acording to the site, she won just over £11 million on the National Lottery. The winning ticket apparently came from a corner shop on Tarrant Road. The Deffry Vale High School website also said the science teacher who won the lottery was Ms Mehru, but then stated that the teacher the Doctor replaced was Ms Barrat.

Ms Barrat
The Deffry Vale High School website stated that the teacher who won the lottery was Ms Mehru, but that the teacher the Doctor replaced was Ms Barrat.

Miss Morrison
The 2015 book The Time Lord Letters by Justin Richards gives the teacher's name as Miss Morrison.

Lucille Beneluct
An in-universe newspaper article in The Secret Lives of Monsters, again by Justin Richards, names her 37 year-old Lucille Beneluct. After winning the National Lottery Thunder-Millions draw, she appararently bought a new basket for Padsy, her Scottish Terrier, resigned from her job as a teacher at Deffry Vale and booked a Mediterranean cruise.