The death of Saima Ahmed, 36, remains unexplained after her body was discovered in January in Edinburgh - 400 miles from her Wembley home.
Her siblings said there is nothing to suggest she took her own life and believe the divorcee could have met up with “the wrong person”.
Sister Saiqa, 37, said she had been buying new clothes and going to the gym before she vanished in August last year.
She told the Daily Record: “Saima was going to the gym, had a doctor’s appointment, had picked up her work rota, was saving to buy a house.
“Why wake up suddenly, take off and say ‘I’m going to kill myself’? And why Scotland?”
Her brother Sadat, 33, told the paper: “She’s possibly met the wrong person or had an arrangement to meet someone that’s gone wrong.
“We’re appealing for anyone who saw Saima.”
Police were alerted to remains in the grounds of Gogar Mount House on the outskirts of Edinburgh on January 9.
They were identified as those of the 36-year-old, who had been reported missing by her family to the Metropolitan Police five months previously.
Detectives believe she most likely travelled to Scotland by train on August 30 last year.
Her exact route is not known but she may have travelled to Hemel Hempstead, Birmingham and then on to Edinburgh.
Police Scotland said earlier this month that they had received only a small number of calls following an appeal for information.
Detective Chief Inspector Martin MacLean said: “Saima’s death remains unexplained as we continue to carry out various lines of inquiry.
“We’re committed to doing everything possible to establish the circumstances surrounding her death and I thank the people who have come forward thus far.”
Saima was about 5ft 5in, of medium build, with shoulder-length, straight dark hair.
She was last seen wearing a long, dark V-neck top and black trousers, shoes and jacket.