Mel Bush: The Character
One of Mel's greatest assets is her wonderful personality, attributable in no small way to Bonnie's energy and enthusiasm for the role.
She has boundless optimism. She is always polite and willing to help others. On numerous occasions, she displays great determination, searching for the Doctor in TATR and reaching the swimming pool in PT. She is a great reformer of people, helping Pex overcome his cowardice and undertaking the task of reforming Glitz from his criminal ways. Unfortunately, as well as being trustworthy, she is extremely trusting, in PT she doesn't realise the Rezzies true intentions until it is too late.
Although easily frightened, she undertakes many acts of bravery, such as traversing the perilous air ducts of the Hyperion to get a message to the Doctor and venturing into the Rani's base. This said, she does tend to scream with alarming frequency in certain adventures.
She tends to speak her mind often, which doesn't endear her easily to others and occasionally gets her in trouble. She's self-righteous to the point of bossiness.
Mel has an excellent memory, causing the Doctor to compare her to an elephant. "It's so ludicrously inappropriate, I find it funny." She remembers the exact wording of the mayday call in TOTV.
Health and Exercise
Mel is greatly into fitness. When she first appears in Terror of the Vervoids she is forcing the Doctor to use the exerciser while she skips with a skipping rope. She also feeds him carrot juice, much to his disgust. She makes use of the Hyperion gym. At the end of The Ultimate Foe, she's keen to get him straight back into the fitness plan. Millennial Rites and Business Unusual also make it clear that she's a vegetarian and has given up caffeine. She also encouraged her workmates at BITS to join a local gym, some of them weren't enthusiastic.
Regeneration is a great aid to weight loss, and with the seventh Doctor on the scene, the fitness fad vanished.
The background story given in John Nathan-Turner's character outline is that Mel met the Doctor on Earth and helped him foil a plan by the Master to defraud the world banking system. Her status as a computer programmer is alluded to several times during her term on the show. She didn't actually get the opportunity to do much programming...
Despite being a computer programmer, Melanie cannot operate the TARDIS. On the odd occasion that she tries, disaster ensues. (from JNT's character outline, 1985)
Mel does get to do some system hacking and programming in Millennial Rites. In Business Unusual she helps clean up the Master's computer mess, and is responsible for shutdown and destruction of SenéNet's systems.
Some interesting extracts from JNT's original outline.
Melanie is one of those annoying young ladies who is a 'feminist' at all times, except at moments of great stress, when she relies heavily on playing the hard-done-by, down-trodden, crocodile-teared female.
Oh, the pain! Where'd this come from?
She has a strong sense of humour and is often heard singing in the TARDIS, much to the annoyance of the Doctor.
La lala la la. They did manage to get her dancing in Delta.
Melanie is the first Earth-UK Companion for twelve years. We shall soon see why.
The Doctor knows the British all turned into fitness freaks in the mid-seventies?