There was nothing conventional about Jemma's childhood.
"I remember spending a lot of time in sleeping bags looking up at the stars," she says.
Packed into their blue and white Land Rover, the family had driven around most of Europe, and travelled from Bali, through Malaysia, to Thailand.
"My mum was definitely a free spirit," Jemma says. "She thought it was a fantastic experience for me to be schooled in the process of travelling and meeting new people."
By the age of 10 Jemma could speak several languages. A year later the family was living on a ramshackle sailing boat on Turkey's Mediterranean coast. But when her mother's relationship with her partner broke down, Jemma and four-year-old Calvin returned with her to Powys in Wales.
"I think my mum liked the idea of having an idyllic cottage with lots of children and dogs, and roses over the door," Jemma says. "And she and my nan were very close, so we came back to Brecon."
By the time Jemma was doing her GCSEs Jemma's mother, Jane, had a new partner - a bricklayer everyone knew as Shakey - with whom she went on to have a boy and a girl, Alex and Billie, 14 and 15 years younger than Jemma.
"Shakey was very charismatic, and I think they had a genuine love for each other," Jemma says, "but he did drink quite a lot."
Shakey liked a pint after work - sometimes many pints. It would get late and Jane would worry. She'd try phoning, but either there was no signal or he wouldn't answer, so she'd get in the car and go looking for him, leaving Jemma in charge of the three children.
"And I wouldn't know when she was coming back," Jemma says.
Once Jane also started drinking heavily everything began to slide.
"When I came home from school, things that would have normally been done wouldn't have been - cleaning the kitchen after breakfast, those sorts of things had been left all day," Jemma says.
Then, while she was studying for her A-levels in 2001, Jane and Shakey decided to move to Andalucia in Spain. They'd been having some financial difficulties as a result of Shakey's drinking, and there was plenty of work there for bricklayers.
"I think it represented a new start," Jemma says, "and from what I could gather the first few months were really positive."
Jemma stayed in Wales with her nan, thinking she might move to Spain after her exams, while Calvin, her younger brother, went to live with his father.
Only a few months later, there was devastating news - Jane had been in a road accident.
Jemma tried to phone Shakey to get more details, but there was no answer. Desperate for information, she put her A-level Spanish to good use and began calling all the hospitals in southern Spain to find her mother.
When she eventually managed to speak to Shakey he was in a state. They'd been crossing a quiet road on foot when Jane had been hit by a speeding truck, he said. In a matter of hours she had died, aged only 40.
"I felt utterly, utterly lost," Jemma says. "Like I was away at sea without any anchor or compass or anything."
Jemma Bere spoke to Jane Garvey for Life Changing on BBC Radio 4 - interviews with people about a moment that has reshaped their life. The programme was produced by Andrea Kennedy.
After Jane's funeral in Brecon, Shakey returned to Spain with Alex and Billie.
"That surprised quite a lot of people," Jemma says, "but I think part of him was doing it because my mum had been happy there."
Jemma still contemplated joining them in Spain, but she had done well in her exams so now had other options too.
"And I decided to go to university - partly because I think that's what my mum would have wanted," she says.
Every holiday Jemma would find the cheapest flight to travel to Spain, giving her uni friends the impression that she led quite an exotic lifestyle. "It wasn't quite like that," she says.
Billie and Alex in Spain, 2002
Billie and Alex, aged 3 and 4, in Zurgena, around 2002
Shakey and the children lived in a small, close-knit community; everyone knew him because he was out drinking all the time, running up bar tabs all over town. When Jemma visited it was obvious that he wasn't coping well. He'd do a building job and spend all his earnings in the pub, or disappear for days at a time after nipping out for cigarettes. Despite becoming increasingly dependent on alcohol, he wasn't willing to seek help.
"We had frequent arguments about it when I went out there - he wouldn't accept that he had a problem at all, he was completely in denial," Jemma says.
"I think he genuinely thought he was doing the best that he could in really difficult circumstances. But he spent more time in the pub than he did with the children."
During term time, while Jemma was at university, Marisa, a nanny Shakey had hired to help him with the children, held everything together.
"She arranged for them to go to a Spanish school," Jemma says, "and she was absolutely wonderful, she adored them."