The 28-year-old from Allerton Bywater spoke about her journey from amateur local race participant to GB squad member at the launch of a new Go Tri initiative aimed at getting beginners into the sport.
Jess joined novice swimmers at Bramley Baths at a session backed by British Triathlon and Leeds City Council, and was keen to pass on her tips to budding triathletes.
The daughter of a swimming coach, Jess showed talent in the pool, but gave up competitive swimming at the age of 16.
"I didn't start triathlon until I was 23, and there was a long time when I did nothing really - I hardly kept fit at all. I went travellling and played a bit of football, that was it."
She was working full-time in a sports centre when she decided to enter her first triathlon.
"I looked around for local events like Leeds and Tadcaster, and I kept progressing to bigger events. I did my first European race when I was still working, but once I got onto the GB programme and was awarded funding aged 26, I was able to give up work."
Although she found the return to the pool easy, Jess had to gets to grips with the remaining two disciplines, cycling and running.
"I had to get used to running, and with cycling it was things like clipping in and out of pedals, which I needed to do to progress. Fitting all the training in was hard too."
She and her fellow Leeds-based GB squad members train for 20-25 hours a week, spending seven hours in the pool, 15 on the bike and 5-6 running.
Jess's favourite running routes take her to spots such as Fairburn Ings nature reserve, while she cycles out to Otley, Burnsall, Adel and Selby. They swim at the John Charles Centre for Sport and The Edge, the University of Leeds's facility.
Her training partners include Olympians Vicky Holland and Non Stanford, who both raced at the Rio Games, placing third and fourth.
"I look up to them - before, I couldn't believe how good they are, now I'm training with them it feels like it can't be right! The Brownlee brothers and Gordon Benson sometimes swim with the girls too.
"I love the variety of triathlon - I hated doing just swimming when I was younger, but with running and cycling you get to see amazing sights, out in the Dales and being outdoors a lot - to do it as a job is a dream."
She is now keen to advise amateur triathletes taking up the sport for the first time ahead of the ITU World Series event in Leeds this June - which will see professionals race alongside age-group participants.
"My advice is to enjoy it! Don't worry about what other people are doing in the race - stick to your own pace and take your time.
"Triathlon has increased hugely in popularity - when I did my first race five years ago, it wasn't nearly as big as it is now. The World Series Leeds race last year was unbelievable - it's my favourite race, and it's a good course. The crowds in other races around the world aren't as good as in Leeds."
Jess is now aiming to secure a spot in the GB women's entry for her home event, and will also compete in World Series races around the world in 2017. She hopes to appear at the next Commonwealth Games.
Leeds City Council has organised Go Tri swim and cycle sessions aimed at beginners at locations across the city, including Bramley, Armley, Middleton and Fearnville. Visit www.leeds.gov.uk/triathlon for more information.