Dr. Gill is the doctor of the village the hunter's move too in 'The Demon Headmaster Strikes Again.' She is hypnotised along with the rest of the village shortly before the Hunters arrive and is recruited by the Headmaster.
As the Headmaster carries out his plans to obtain Dinah's DNA so he can create Eve, he finds the doctors profile on his console at the BRC and thinks she will be useful for this particular task. Dr. Gill is sent to The Hunter's House and lies about how the hospital requires the families swab samples for a possible cure for Lloyd's condition, thinking it may help Lloyd, they all have their swabs taken.
Simon spots Dr.Gill head straight back to the Biogenetic Research Centre to complete her task, when he tells Dinah about his discovery she dismisses him as the doctor at the hospital has already received the rests so he must be mistaken.
Dr.Gill isnt seen after this however she did her part in the creation of Eve and helping the Headmaster with his plans.