Boxing, of course, will always be her number one priority.
But on her days off she takes a speedboat out for spins on the Connecticut river, a 30-minute drive from her US home in the city of Vernon.
"I was out kayaking one day, and I saw a little speedboat going out on the lake. I just got a bit of an urge to test one out. It just looked like great fun. That's pretty much how I got a passion for speedboats," she suggests.
She ended up buying one.
"It was a bit of an impulse buy but it's been just a great buzz. It's a great way to spend a bit of time off, being on the water.
"There's just something about the water. It's so peaceful out there, I could spend all day on the water, really. Just by the sea, by the lake. I just love times like that."
Katie is still learning her nautical skills and hasn't gone out on her own yet.
"I usually go out with a few friends. I still can't dock the boat yet. I need someone else there with me to actually dock it. I'm still learning."
Career-wise, Taylor has had another busy year. Though there have been no career-defining fights, she defended her four World lightweight belts in May and September and wraps up 2021 next weekend in Liverpool.
She is looking forward to a break over Christmas with her family back in Bray.
In 2022, she embarks on what could be a defining year in her career with the possibility of a spring showdown against Amanda Serrano in what would be the richest ever pro fight in female boxing.
"I actually only got home for a week after the last fight and then I came straight back over here [to Vernon] just to start training because I assumed I was going to be out again before Christmas.
"It's been pretty much all go since then. I've just been getting my head down, continuing to work hard and I'm so glad that we were able to nail down a fight again before Christmas."
Next weekend Taylor bids to make it 20 pro wins on the spin against a little-known opponent, Firuza Sharipova, who is the first-ever female professional boxer from Kazakhstan.
Sharipova suggested recently on Instagram that she would knock both Taylor and Conor McGregor out on the same night.
Taylor never allows herself to be drawn into verbal spats before fights.
She just laughs and remarks: "I don't really take too much notice of what people are saying, or what the opponents are saying, really. I had no idea that's what she was saying.
"But I'll just get my head down as per usual. I'll never need any help in there: all of my preparation will always be spot on.
"I always expect the toughest fight possible and I'm always willing to dig deep and to go wherever I need to go in order to win the fight.
"So, regardless of what she's saying, I'm never one for speaking before a fight. I just get the work done in training and do my talking in the ring. This fight is no different."
On her Christmas visit home Katie will make one girl's dream come to pass when she does a full boxing training session with her.
Eleven-year-old Addison Whelan, who plays soccer with Shelbourne U-13 team and boxes out of Corinthians Boxing Club in Dublin city centre, hit the headlines last month when she secured Cristiano Ronaldo's jersey after the Republic of Ireland v Portugal game at the Aviva Stadium.
Later she got a phone call from Taylor offering her a training session. A friend of Taylor's, who is a cousin of Addison's, rang Katie in the US and told her the story.
"My friend sent me a clip of her [Addison] hitting the pads and she's obviously a huge boxing talent as well. So I just told her that I'd seen her hitting the pads, that she was so impressive, and I told her that I'd do a training session with her once I get back home after this fight.
"I'm looking forward to actually meeting her in the flesh and having that training session with her."
Taylor, of course, was a talented soccer player, winning 19 international caps at senior level. She might conceivably still be playing for the Republic of Ireland had she not decided to focus on her boxing career.
She still follows the team's fortunes and is impressed by their performances in the World Cup qualifiers.
"I have been keeping my eye on that. They seem to be doing brilliant at the moment."
But she has given away all her soccer mementos
"I think I've given all my soccer jerseys away, to be honest."
Halloween marked the 20th anniversary of the first-ever sanctioned female fight in Ireland in the National Stadium in which Katie featured.
Though the then 15-year-old had big dreams, she still never imagined that two decades later she would be rated as the best pound-for-pound female boxer in the world.
"As a 15-year-old, as a kid, I always had big dreams, big hopes. I wanted to make an impact in the boxing world. My whole childhood was obviously based around this Olympic dream that I had.
"But never in a million years did I think I'd be in the position that I'm in now. Having the chance to box on the biggest stages in the world as a professional fighter has been absolutely fantastic.
"Just to see where women's boxing is right now and see the number of female fighters. It's been a golden moment for women's boxing, really, over these last few years and that, for me, is everything. I couldn't have imagined as a 15-year-old that it would be where it is now. It's been a dream.
She credits her parents for helping realise those dreams.
"With the environment that I was in, I'm very, very lucky to have been surrounded by a family who were so encouraging.
"My parents always made me believe that nothing was too big for me - and that if I worked hard and got my head down, that it wouldn't be too big for me.
"You are a product of your environment ... and those encouraging words always stayed with me, even during times where I actually doubted whether or not this was going to happen."