She spent nine years looking for her Lebanese birth mother, only to find her living an hour away from the Swiss village.
She spent nine years looking for her Lebanese birth mother, only to find her living an hour away from the Swiss village where Guigan was raised by her adoptive family.
The process of tracing her birth mother is one that many of those adopted abroad during Lebanon's 1975-1990 war have started.
But such searches are often complicated by reams of false paperwork and secrets that many people would prefer remain buried.
Zeina Allouche, co-founder of the Badael-Alternatives NGO, estimates that at least 10,000 Lebanese children were adopted during the war.
International adoption began before Lebanon's conflict but ballooned during the war, with middle men and local officials aiding the process by producing falsified paperwork, often for a fee.
"It was easy," Allouche told AFP.
"It was a gang time: no laws, no safety, and there was a kind of complicity because people thought this was a good way to save kids."
Guigan's adoptive parents collected her in 1984 and she grew up mostly in Switzerland, knowing she was adopted but with no information on her birth family.
When she was 18, her adoptive parents gave her a file including a "certificate of abandonment" from her birth mother.
"This is where I got very lucky -- her real name was on it," she said.
It was a lead, and more than many adoptees begin with, but it still took Guigan nine years, multiple trips to Beirut, and the help of a Lebanese television crew to find her mother.
"I really didn't believe that this could still be possible in this life," she said.
"I did a lot of internal work to prepare myself for the worst. So meeting her and knowing she's alive... was one of the most beautiful experiences I've had."
Sophie, who asked to be identified by a pseudonym, was adopted by a couple living in France in 1966, before the war, and began her search in her 40s.
"I felt the need to fill a profound void, to know the story of my birth," she told AFP.
Armed with her mother's name, she went to Lebanon to research her roots but encountered resistance.
People told her "'You already have a family there! You were lucky to leave here!'," she said.
"They didn't understand why I was looking and it seems to me the subject remains delicate and taboo in Lebanon."
Allouche said many adoptees encountered similar responses. Some were completely rejected by birth families seeking to avoid the perception of scandal.
Badael tries to help in various ways, including the online listings that contain fragments of identifying information, and advice on search methods such as DNA analysis.
That was how Sophie finally found her biological mother: DNA tests with several online companies uncovered a first cousin, who she searched for on Facebook.
That led her to another first cousin who was "completely aware of my existence", she said.
"His father, my uncle, had helped my mother search for me after my birth and in the years that followed."
She learned that her mother had emigrated to Australia and they are now communicating through Sophie's half-sister.
"I'm relieved and so happy to have finally found her," she said.
She has become a strong proponent of DNA analysis and hopes more birth mothers seeking their children begin using it.
Many wartime adoptions were facilitated by diaspora Lebanese. Terri's adoptive parents turned to a colleague whose mother was living in Lebanon.
"They asked, and she just miraculously found a baby waiting," he said.
Ten-month-old Terri left Lebanon in 1988, and as a child often wondered about his birth and adoption.
"I didn't know what a war was, so I just imagined a big room full of people fighting, and this baby on the floor."
He is desperate to trace his birth mother but has few leads, including a document saying he was abandoned on the doorstep of the Sayidet al-Maunat hospital in Byblos, north of Beirut.
A trip to Lebanon proved fruitless, but tests through the DNA analysis site 23andme revealed a first cousin.
"That's the closest blood relative I've heard of. But he's not really interested in giving me information. He just kind of wished me good luck."
Terri's search is complicated by the fact that he is transgender, having been assigned female at birth but transitioning to male in his 20s.
Badael has registered 2,700 children adopted from Lebanon in its database, and a handful of mothers seeking their children.
Allouche said adoptions decreased after Lebanon's war ended, but the numbers are rising again with the conflict in neighbouring Syria, which has displaced millions.
"I was contacted personally because they thought we could facilitate adoption of Syrian refugees," she said.
She expects Syrians adopted during their country's war will one day undertake the same search as people like Terri, who is still hoping to find his birth mother.
"I feel like there's a blood connection that might be unbreakable and strong... I would really love to meet the person who gave birth to me," he said.
"It would be some kind of closure."