Sarah McGill, 28, was arrested at a hotel in Orlando, Florida, on Saturday, April 7, accused of having sex with a 14-year-old.
She was later charged with lewd and lascivious battery, an offence carrying a jail sentence of between five and 15 years.
Florida police say the teenager had made contact with a woman named Sophia Belle, an alias used by McGill, while searching for prostitutes online.
The boy said that he had gone to a hotel to have sex with her, and paid her $480, around £340, afterwards.
Police later found McGill, a former Borders College student, in the same hotel room and identified her from her UK passport. They reportedly discovered condom wrappers, cash and unused condoms in the safe.
She was taken to Orange County Jail and later released on bail after posting a £1,000 bond, but she has been ordered to stay in Florida to attend trial.
McGill, brought up in Selkirk but now living in a flat in Church Square, Galashiels, was also told not to engage in any online activity.
Her ex-girlfriend Emma McWatters, 27, said she was surprised but not shocked after chancing upon the news online.
“I was surprised to see her face pop up but not shocked,” Emma said. “She’s always been like that. I just thought ‘she’s finally been caught’.
“She was very quiet when we were together. You would never have thought she was like that, but she’s been doing this since she was 14 or 15.
“It said in the report that she was unable to sign the court papers because of mental health, and that is probably right. I think it is something mental.
“She did get counselling for sex addiction when she was 16. I think she was born like that, to start that young.”
The two met as teenagers at a rock night at the old Liberal club in Hawick when McGill was 14 and Emma was 13. They were together for five years, during which time Emma claims McGill was repeatedly unfaithful to her.
She said: “At the beginning, we were very close, then she started making excuses, saying she was babysitting or whatever.
“She ran away when she was 15, and they found her in London with a 50-year-old man. Her mum got a court order so she couldn’t leave Selkirk.
“When she came back, she died her hair black, and we just carried on. I was a mug. I didn’t want to bring it up. I didn’t ask the questions because I didn’t want to know. I was young and in love.”
Nowadays McGill seems to be leading a double life. On the Sophia Belle website promoting her escort services, taken down since her arrest, she asked for “donations” of up to £2,000 for her “time and companionship”.
According to her social media profiles, though, she is a professional clinical hypnotherapist and runs her own business in Edinburgh.
“I think that’s a load of nonsense. She’s never been into that kind of stuff,” Emma said.
“She is abroad a lot. She usually has a main client who pays her ticket and she goes over to different countries to meet up with them and others.
“This publicity will bring her more custom. She will just change her alias and carry on.”
The two haven’t been in touch since Emma got married six years ago, but she says it was disconcerting when she discovered online that her ex-girlfriend was facing time in an American prison.
“She’s looking at 15 years,” she said. “I’m not entirely sure how I feel about it. It’s brought a lot of emotions up for me from the past. She was my first love.
“I think some jail time would do her some good, but she’ll never stop. She’s not evil or vindictive, she’s just needy and obsessed with sex.”