She now devotes her time to preserving his legacy: in addition to a recent boxed set, she is overseeing next week's release of a tribute album on iTunes and the unveiling, by Gibson, of a commemorative 'Pretty Woman' 12-string Epiphone guitar, both events tying in with what would have been Orbison's 73rd birthday yesterday.
The tribute album, Under The Covers, finds younger artists such as Ben Taylor and the LA rock band Rooney covering classic Orbison tracks, stressing his songwriting skills.
'When you are dealing with a voice like Roy's, the singing tends to overshadow everything else,' Barbara says.
'When Roy sang a song, other vocalists were scared to tackle it, but I think that's wrong. Classic songs can help new artists. Simon Cowell has proved that. Carrie Underwood, the American country star, sang one of Roy's songs, Crying, and she won American Idol.'
Barbara began dating Roy two years after the death of his first wife, his childhood sweetheart Claudette Frady, who died in his arms after a motorcycle accident in Tennessee.
When Roy and Barbara met in 1968, the singer was in the middle of a UK tour. Barbara had flown over from Germany to visit a girlfriend who was studying in Leeds.
It was, she admits, love at first sight, and the couple - who went on to have two sons together - got married in Nashville just four months later.
'I met him in Batley, in Yorkshire, on my first night in England,' says Barbara. 'At first, I didn't even want to talk to him because I wasn't the kind of girl who was impressed by famous people. But there was obviously some interest from Roy, because he really wanted to meet me.
'Then, as we chatted, I was struck by what a nice man he was. He was so easy to be around. He focused totally on our conversation, and he also gave plenty of attention to the fans who had come to meet him. In the end, it was a great love story.'
Only months after the couple met, however, another tragedy struck when two of Orbison's three sons from his first marriage, Roy Dewayne, ten, and Anthony, six, were killed in a house fire.
The singer's fortitude in dealing with seemingly insurmountable grief would later be an inspiration to Barbara when, in 1988, she had to come to terms with her husband's own death at 52.
'Losing the children was a very dark time for Roy,' she says. 'But he was so strong in the way he dealt with it. He wasn't a particularly religious person, but he had a lot of faith in God.
'I took strength from the way that he walked through it all. Grief comes and goes in waves, and you just have to put one foot in front of the other.
'When he flew home after his sons had been killed, he refused to take a private jet. He told me he would have cracked up if he'd done that. He felt it was good to queue up and show his pass at the gate because that was normal.'
Orbison's career dates back to the early days of rock 'n' roll. Born in Texas, not far from childhood friend Buddy Holly, he was making records in Memphis's legendary Sun Studios around the same time as Elvis Presley, Johnny Cash, Jerry Lee Lewis and Carl Perkins.
But it was in the Sixties - when he turned his otherworldly, fouroctave voice to lovelorn ballads like Crying and Only The Lonely - that his career soared.
While other American stars floundered, Orbison flourished during the Brit-dominated beat boom. He went on the road with The Beatles and toured with The Rolling Stones, who deferentially called him 'Mr Orbison'.
'When Roy started out, there was no road map for pop,' says Barbara. 'When he was with Elvis in Memphis, they didn't even know whether they'd last six months. They were pioneers.
'In the Sixties, he was never out of the news. He got the kind of coverage that Paris Hilton gets today.
'No band ever wanted to go on stage after him. When he played with The Beatles, they asked him if they could close the show. Roy wasn't bothered, so he agreed. But he went down a storm, and John and Paul began to regret it. He was a hard act to follow.'
Given that Orbison died just as his career was scaling fresh peaks, Barbara believes, rightly in my book, that he would still be making relevant music were he around today.
After all, he was never happy to rest on his laurels. He worked with Rick Rubin long before the latter rejuvenated the fortunes of Cash and Neil Diamond, and collaborated with T-Bone Burnett, the producer of Robert Plant and Alison Krauss's Grammy-winning Raising Sand.
'I think he would now be seen as a contemporary of Bob Dylan and Leonard Cohen,' says Barbara.
'But he would have attracted younger producers, too. I know that Jack White, of The White Stripes, is a fan. Jack did an album with Loretta Lynn, and I'm sure that he and Roy would have worked well together.
'Nobody ever figured out quite where Roy's sound came from, but his reputation just keeps on growing. He was an original, and people are still saluting his talent. For me, that is incredible.'