Anne Bury, 56, from Swainby in North Yorkshire, was murdered at her villa in Dalyan in September 2013.
Her elderly mother Cecilia, 87, and 25-year-old son Alex were also injured in the shooting.
Gardener Veli Acar, who was jailed on Wednesday at a Turkish court, had claimed the pair were in a romantic relationship which the family denied.
After his sentencing, the family said Ms Bury had intended to dismiss Acar, then aged 46, as her property manager after discovering his "dishonest and deceitful nature".
"We also know that Anne's killer was aware of what she intended to do and believe that Anne was killed in order to prevent her from doing so, as this would have revealed to his family and friends the lies he had peddled of a romantic relationship with Anne and the illegitimate source of his new-found wealth," a statement from the family said.
They added she had been unable to defend her reputation but had left "irrefutable documentary evidence" proving there was no romantic relationship and Acar was simply trying to cover up stealing from her.
Ms Bury, a trained midwife, worked in a healthcare role for an oil company in Dubai. She had also worked as a barrister specialising in health and social care.
She was described by her family as a "caring, compassionate, considerate and trusting woman".
"Although justice has been done, nothing can bring back Anne or restore the grievous mental and physical wounds inflicted by this evil man on Anne's mother, son and wider family which will be with us for the rest of our lives," the family added.
The family of a woman shot dead in Turkey have said justice has been done after her killer was jailed for life.