Cut Barker open and she'd bleed black and white having gone to watch the men's team for as long as she can remember, and now she dons the iconic number nine shirt for Becky Langley's side.
That's a far cry from turning out for rivals Sunderland earlier in her career, but she's never looked back after making the switch from red and white to black and white in 2020, helping United to achieve back-to-back promotions over the last two campaigns.
"I remember always having a ball at my feet and football has always been a part of my life," Barker told newcastleunited.com.
"I used to just play with friends at grassroots level for a long time and never took it seriously until I was 15 or 16 and into the last year of my RTC (regional talent club).
"I think at that age, something just clicked where I thought maybe I shouldn't just stay playing with my friends and that I can progress and keep getting better."
Barker has a long-standing working relationship with Langley dating back to their days at Northumbria University, where United's head coach was previously Head of Women's Football, but they could have been working together in another way had things panned out slightly differently.
Growing up, being a full-time footballer was nothing more than a dream for Barker and many other girls, so she considered other ways to ensure she always had a connection with the beautiful game.
"If I wasn't playing football then I definitely think I would be coaching," Barker added. "I've always loved football because it's a part of me and always will be."
The summer of 2020 proved to be a significant one for both Barker and United as she left Wearside to once again link up with Langley and lead the line on Tyneside.
But Barker departed Sunderland with memories and experiences to stay with her for a lifetime, including debuts in the Women's Super League (WSL) and the Continental Cup - a competition United will play in next season - against some of the country's best players.
"I went to Sunderland at 15 for one final year of an RTC and then as soon as I turned 16 I started playing for the development team," Barker explained.
"Then at 17 I got into the first team, playing a couple of games. One was in the Continental Cup and one in the Women's Super League. I was certainly thrown into everything quite young and fresh.
"I can't remember if I got a call or a text but it was to say that I would be involved, but I wasn't sure if I'd actually get on. I just thought I'd be there to make up the numbers. It was an amazing experience for me to make my debut in the Conti Cup against Aston Villa.
"Then I came on against Arsenal in the WSL, which was amazing. I remember when I went on against Villa my legs were just trembling and I didn't have much to do but it was an amazing experience."
Playing in the WSL certainly helped Barker take to life in tier four like a duck to water as she smashed in 30 goals during her first full season with Newcastle.
United's number nine saw her first campaign cut short due to the Covid-19 pandemic but not long after returning to the pitch, Newcastle were moving forward off it as well.
"It was during Covid (signing for Newcastle) and I knew Becky through university having played football under her at Northumbria," Barker went on to say.
"I was coming to the end of my time at Sunderland with it not working the way I was hoping it would. I had a lot of trust in Becky and a lot of things were starting to move in a different direction at Newcastle.
"The plan was never to go full-time but things changed so quickly when I arrived; the club was under a different ownership so I don't think it was an option back then.
"I don't think I could have ever imagined that my time here would have gone so sweetly, especially being a Newcastle United fan. It's just what dreams are made of."
For the majority of people who grow up in and around Newcastle there is one dream, and that is to play in the famous black and white shirt on the cathedral on the hill.
The majority of people never get to live out that dream, but Barker is one of the fortunate few - and no matter what happens in the rest of her footballing journey, Newcastle's number nine's name will forever be etched into the club's history.
In 2022, Barker popped up at the Leazes End and scored against Alnwick Town Ladies on the penultimate weekend of the season, becoming the first female player to score at St. James' Park.
"It still doesn't feel real at times," she admitted. "Having gone to the men's games as a little girl I never once thought I'd be out on the pitch playing at St. James' Park.
"The day before (the Alnwick game), Newcastle United men's team had played at home and I remember watching the players come out the tunnel with Local Hero on and I started crying because I knew that was going to be me.
"To have been the first woman to score there is something that will stay with me for life.
"That celebration still gets talked about all the time. There are still the iconic photos from when I did the Shearer celebration and I love it.
"I felt as if I was always going to score that day; maybe not so sure about it being the first goal, but I was sure I was going to score."
Her time on Tyneside has featured several more memorable moments and very few lows, so when quizzed on her highlights so far in a black and white shirt, Barker was not short of options.
She's played at St. James' Park four times in competitive matches and won two league titles as well as a Golden Boot, but there was only ever one true highlight for the number nine.
"It's got to be getting promoted back into the Championship during my first season as a full-time professional and getting promoted," she revealed.
Barker has been deployed in several different positions including left-wing, centre-forward and in a number ten role during her time under Langley, but was quick to point out she isn't all about what happens at the top end of the pitch.
In the 2021 Women's County Cup final, Newcastle were left without a goalkeeper when Laura Wareham was forced off with an injury against Wallsend BC Women Reserves and with no keeper on the bench, Barker emerged as the resident emergency shot-stopper.
"Not only am I a striker, winger or a number ten, I'm actually a goalkeeper like in the cup final," Barker proudly said.
"For anyone who hasn't seen that save I made against Wallsend, go look it up! I'm always the back-up player to go in goal if someone gets injured."