The 51-year-old public relations executive and events organiser was smoking 30 a day, having started at the age of 14. She had never tried to stop before but had been "constantly ill" between Christmas and April with a run of colds and chronic bronchitis, which had made her think about giving up. "Truthfully, I never thought I could do it," she says.
That was five months ago. Now, the glamorous woman turning heads in a city-centre restaurant is aglow, not only with much improved health, but with boisterous delight at having succeeded in cutting cigarettes out of her life.
"The difference is massive, I cannot tell you how I feel," she says enthusiastically, breaking into joyful laughter. "I haven't had any colds or infections, and my chest: I've got a wee dog and I can run. I was never able to run, I was always panting and breathless.
"And the other big benefit is my skin – all the lines have disappeared around my mouth. I've got a glow about me. I think my confidence has gone up because I've conquered this thing I never thought I'd conquer in my whole life."
Giving up cigarettes is beneficial at any age. A recent study showed that women who quit smoking before the age of 30 reduce their chances of smoking-related death by 97%, and before 40 by 90%, but that does not mean there is no point to giving up over 40; far from it.
Mima Muir, a health improvement practitioner who works for the NHS in north-west Glasgow and helped Jessica stop smoking, says: "No matter what age you are, there are health benefits. Stopping smoking, you immediately reduce the risk of illness, disease or death caused by cancer, heart or lung disease.
"After 20 minutes, your blood pressure and pulse return to normal; 24 hours later, the carbon monoxide is eliminated from your body and your lungs start to clear out the tar that has been clogging them up.
"Forty eight hours later, the nicotine has gone and the sense of taste and smell start improving, and three days later exercise becomes easier. By attending free, local and effective NHS Stop Smoking groups, you are four times more likely to quit successfully. The groups are relaxed, friendly and informal."
For Jessica, the push she needed to stop came in the form of VIP tickets for the London Olympics. She was invited by her brother, Donald, whose horse Flying Finish had been selected to take part in equestrian events. He invited Jessica to accompany him to three days of VIP parties where they would meet Kate Middleton and Princes William and Harry. Jessica was thrilled, but then discovered smoking was banned near the hospitality area. Her first thought was that she couldn't go, but then she resolved to use the added incentive to stop smoking. On the advice of her GP Helen Jackson, she signed up to smoking cessation classes.
Her first attempt to stop, three weeks in, faltered but by week four she had emptied her flat of all cigarettes and, with the help of some NiQuitin patches, she finally stopped. By the time of the Olympics, she was feeling great, and while regaling Prince Harry with stories at Greenwich Park she didn't miss the tobacco one bit.
All in all, she rates quitting smoking as the best thing she's ever done and now wants to retrain as a smoking cessation counsellor. "Everybody's got their timing; my timing was this year," she says. "It's never too late."
For help to stop smoking, visit www.canstopsmoking.com or call Smokeline Scotland on 0800 84 84 84, 8am to 10pm.