Much of her life is left unexplored in the series and the novels, all that is known is that she had risen to be the head of mechanoid deign at DivaDroid and was most likely involved in the production of the unsuccessful Series 3000 mechanoids who were disliked for being disturbingly human. It is possible that this debacle might have been what brought her to be the company's main designer, though she might have been that before.
She got involved with a fellow bio-engineer named John Warburton and the two became engaged. However, just before their wedding he fled, which caused a deep level of resentment in Mamet. In revenge she designed a mechanoid meant as a cruel depiction of him - pompous, ridiculous looking and overbearing. Further, all their negative emotions are stored on a "Nega-Drive" and when it becomes full they literally blow up as a symbol for his supposed temper. This design was accepted by DivaDroid and made into the 4000 Series, such as Kryten, which proved much more successful, probably due to their over-the-top edge making them far different from their unnerving predecessors.
It is assumed that she continued working for DivaDroid on later models, such as the Hudzen 10, and she might also have been involved in the design of the Data Doctor configuaration and repair software for mechanoids. It is unknown how and when she died, just that it is unlikely that she lasted three million years.
All Series 4000 mechanoids are programmed to obey her every command and every cell of their bodies is programmed to make them unable to harm her. It is unknown if this was a vanity feature or possibly a safety feature during testing. Nevertheless it actually proved to be a security weakness as a Psiren, a type of GELF that telepathically lures its victims, was able to use it to manipulate Kryten into putting himself into a trash compactor. She appeared as a middle-aged woman wearing a futuristic, silver uniform with high boots. Unlike with the other Dwarfers Kryten was fully aware of what was going on, but was just unable to resist the illusion. This enabled him to jump, his now cuboid self after being crushed, onto the creature's head, saving Lister and the Cat.
Her other legacy would prove equally troublesome for the Starbug crew when they come across the SS Centauri in the Series VII episode "Beyond a Joke" and its Simulant and Kinitawowi crew - plus an outrozone-addicted Series 4000 named Able. Before they knew the ship was inhabited they completed a successful scouting party bringing back many rare luxuries - including a lobster. Kryten cooked it up fancily to celebrate the anniversary of his rescue from the Nova 5 and was annoyed when the others are more interested in a total immersion video game. After sabotaging the game, he finally blew his top a la Warburton when Lister requested ketchup. Blowing out the rest of his Spare Heads whilst trying to repair them they realised they needed to find more on the Centauri.
They traded with the simulant for the heads, in the guise of GELFs to avoid the machine's anti-human drives, only to find it to be a diversion whilst the simulant's GELF crew member ransacked the ship - including Kryten's body and memory sticks. After tricking the Centauri back using a fake bomb threat, the crews faced off in Starbug's cargo bay where the simulant revealed Mamet's secret password for the file on the nega-drive to the now repaired Kryten - who becomes shocked and despondent. Able saved the day by knocking out the simulant while Lister took out the GELF. It was this truth which turned Able into a "zonie". Kryten eventually got over the realisation with help from Lister, and even gained respect for his drug-addicted "brother" after he sacrificed himself for the rest of the crew in a final battle against the simulant using the nega-drive.
Behind the scenes
Presumably, the character at least may have been named for American playwright David Mamet.