She made her debut at the age of 16 in November and despite her tender years didn't look out of place. The right-back, who can also play centre-half, was calm, assured and purposeful.
Now she is a fully-fledged member of the First Team squad after completing her progression through the RTC and Academy ranks.
The England Under-17 international reported back with the her teammates to the Trillion Trophy Training Centre, Wast Hills, this week and is preparing for the likelihood of regular involvement in the WSL.
And it is something that she is taking in her stride.
"The Club have asked me to step up, be involved full-time, to get to know the girls even more and improve upon last season, just build on what I have been doing really," Simkin told bcfc.com.
"If the girls need me to help out then I'm prepared to do whatever job I can for the team. I wouldn't say there's any pressure on me, I don't really feel pressure much.
"It all happened so fast last season due to players dropping out due to injury. I didn't really have that much time to think about it (her promotion to the senior squad and debut).
"But now, looking back, I've gained so much from the experience and it has helped me to progress to where I am now.
"We are all excited to be in training, we are ready to go again. I just want to try and get as many minutes as I can and help us do well."
Simkin came on as substitute at Brighton & Hove Albion for her debut and then started the next match, which unfortunately didn't go as planned as Chelsea ran out heavy winners at Solihull Moors. But she was unbowed by that scoreline and the obvious extra demands compared to playing youth football.
"The main difference is communication and physicality. The football side of it, it is faster. But the communication between the girls and the relationships you build with players on the pitch means a lot more than if you were playing Under-16s.
"One switch off and it's a goal in the WSL. Especially being a defender, one mistake at the back could end up losing you a goal and three points. So the concentration and focus is big as well, definitely."
Simkin, who went on to play six times, admits is was fairly daunting initially.
"The first couple of times I came training it was quite intimidating with some of the older, more experienced players. Kerys Harrop, Lucy Staniforth, Rachel Williams have all been around. But they were all mega supportive.
"In the Brighton game itself, Freya Gregory went down with cramp, there was such little time to prepare as I had a quick warm-up and then I was on. Once I started playing I felt OK, it was like a normal game of football.
"Then the next game I was starting against Chelsea. I found out a couple of days before and the nerves had time to kick in. But the girls reassured me in the changing room and it turned out to be a really big moment in my career.
"Yes the result wasn't great. But playing against some of the players I was against - some of the best in the world - it was a great experience to add."
Football is in the genes for Simkin. Her father, Darren, played for Wolves in the 1990s. He was also a right-back and centre-half.
It was no surprise that she began playing herself and at a young age she joined her local club, Wyrley Juniors.
"My dad played and that was inspiring, my brother played at a decent level. I used to play in the streets with all the lads on the estate and my mum took me along to Wyrley Juniors, which is a sister club here.
"I went to their Wildcats. When I was seven I joined the boys team. I was the only girl. I was with them until joining Blues at 10.
"My team was really accepting. They were happy having me there. Without that I wouldn't be where I am now, you had to have the determination and grit to compete and get the ball back as you were against boys."
Simkin's journey through the Blues system to First Team means she is now seen as a role model for the next generation of aspiring young girls. That is another thing that sits comfortably with her, having watched her own local heroes at first hand.
"I've watched Connie Scofield play for years and she's a role model to me. I remember when I joined the under-11s, I looked up to Connie who was playing in the under-17s.
"I had a season ticket at the Moors to watch the women play.
"During the break I have been helping out with the under-10s now, doing some coaching. It's nice to see them and they recognise me."
The parallels with the Men's team and the emergence of another highly talented teenager, Jude Bellingham, is interesting.
The way Bellingham took everything in his stride and didn't get carried away, resulting in a world record move for a 17-year-old, to Borussia Dortmund, was hugely impressive.
Simkin shares a similar grounded attitude and focus on what matters most: the football.
"From the call to say I was training with the first team last season to the call to say I was promoted to the group full-time, it's just been about staying level headed and being prepared to know that anything can happen at any time.
"So when there was an opportunity to jump in (last season) you had to take that opportunity and I think that's what I did and that's why I'm here now."
The Barclays FA Women's Super League season is aiming for a start date of 5-6 September.