Family friends told how Jeni Ayris, 46, was preparing to leave the war-torn country to fly home to Scotland this weekend.
She died when a female insurgent drove a car full of explosives into a minibus carrying mainly foreign workers in Kabul on Tuesday.
Her last message on social media stream Twitter just a few weeks ago said: "[Jeni Ayris] Is back in Afghanistan and wondering what lies before her this time?"
Friend Michael Hodgson, 39, said he had been due to meet Ms Ayris and other friends on Sunday in Edinburgh – where she previously ran Ndebele, a South Africa-themed cafe.
Mr Hodgson said: "Jeni Ayris was a warm, kind and generous person with an everyday objective of helping everyone she met. She had a positive boundless energy which rubbed off on everyone, making her loss all the more hurtful."
Ms Ayris was born in Durban, South Africa, and moved to the Scottish capital 17 years ago.
She held dual citizenship, travelling to Afghanistan on a British passport.
She was working as a customer relations manager for South African aviation company ACS/BalmOral, which arranges flights for charity workers and other helpers.
Ms Ayris, whose sister Patricia also lives in Edinburgh, is thought to have travelled to and from Afghanistan a number of times in the past 14 months.
Mr Hodgson added: "Jeni leaves behind a sister who is her only family, as well as a huge number of friends across Scotland and the world.
"We are all absolutely devastated by her tragic death."
She had her home "firmly rooted" he said, adding: "For 10 years she was a popular figure in Tollcross, where she ran the Ndebele South African Cafe and Delicatessen.
"Jeni was highly respected and valued in her job as a manager in the aviation sector, where she was responsible for the safe air travel of NGO [non-governmental organisations] personnel throughout Afghanistan.
"Her contribution was her practical way of helping that country move forward."
Another friend, Richard Kellett, from the Isle of Mull, said: "This has come as a real shock."
Hundreds of heartbroken friends paid tribute on Facebook, describing her as a "great cook who loved entertaining" and "an inspirational character".
Woodstock Taylor said: "Dreadfully sad to hear this news about such a lovely person who used to brighten up my neighbourhood. Ndebele was a brilliant place and Jeni was a ray of sunshine around Tollcross.
"The cafe is much missed, and Jeni will be far more so."
Michelle Atkins-Berlagoski posted: "Our thoughts and prayers are with Pat during this very difficult time."
Of the 12 people killed in the bombing near Kabul airport on Tuesday, eight are believed to have worked for ACS/BalmOral and the other four are thought to have been Afghan citizens. Eleven people were injured.
In a statement, the company said: "ACS/BalmOral is deeply saddened by the loss of the lives of some of our staff in Kabul, Afghanistan, due to a suicide bombing attack that occurred on September 18.
"We are in the process of notifying the next of kin and our main focus now remains with the families of the innocent victims who tragically lost their lives.
"Our prayers and thoughts are with them and all our staff remaining in Kabul."
Islamist militant group Hizb-i-Islami said it was responsible for the attack, which was carried out by a 22-year-old woman in response to the anti-Islam video clip ridiculing the Prophet Mohammad posted on the internet last week.
A spokesman for the Foreign and Commonwealth Office said it was providing consular assistance.
