|Portrayed by||Daniela Denby-Ashe|
|First Appearance||Series 4 Episode 16|
|Last Appearance||Series 4 Episode 16|
|Cause/Reason||Sacked for her web of lies|
Jem Allen was a supply teacher in Series 4 Episode 16. She claims to be a big shot with lots of money and friends in high places; she tells music teacher Matt Wilding that a friend of hers called Hermione works for BBC North West, and is coming to the school to do a feature on his school choir, but when nobody turns up, Matt phones the BBC about it only to discover that nobody there has any idea who Hermione is or what he is talking about.
Later, she and Grantly Budgen take a coachload of students on a trip to what was supposed to be the Royal Exchange Theatre in Manchester, but on the way there she redirects them to what she claims is her boyfriend's house, a huge, expensive mansion with its own indoor swimming pool. The students do what students do, drinking alcohol and messing about, leaving the place in a state, until they end up at the swimming pool, and a prank by Paul and Philip goes badly wrong, leaving Bolton Smilie unconscious in the pool. Grantly Budgen jumps into the pool and pulls Bolton out, then suffers what is believed to be a heart attack (next episode is revealed to be kidney stones) at the poolside and is rushed to hospital, but just before he suffered the “heart attack” he exposed Jem's lies, after discovering the truth by snooping through some files - Jem does not have a boyfriend who owns the house, she is merely house-sitting for a Mr and Mrs Birkett.