A lay-up machine at that stage, Thornton concedes she’s a different player now. At Quinnipiac college, she added an outside shot and slotted into a more structured offence.
“I was really focused on being a pro, that was always my goal from when I was 16 but then I learned what it was like. Basketball wouldn’t hold the same appeal to me if I had become a pro. I had to go to America to understand basketball isn’t who I am. I love it, absolutely love it, but I want my education too.”
Thornton’s experience Stateside was positive though. The university made it all the way to the Sweet 16 stage of the prestigious March Madness and multiple trophies in their own conference during the four seasons.
The youngest of four, growing up around Alan, Jason and Frank and with the support of parents Seán and Christine, Edel’s family gave her the strength to thrive across the Atlantic.
Her father had a strong hurling connection with St Vincent's while her eldest brother Alan was a serious soccer player until injuries wore him down. As a primary school girl she did Irish dancing for her nan and dabbled in a bit of camogie.
Once she started bouncing a ball in the Parochiall Hall she never looked back.
Thornton was part of a golden generation of Brunell players along with Amy Waters, Aoife Dineen, Megan O'Leary and more who went from U12 upwards without losing a game on Leeside.
"We'd a very good team, no doubt," she recalls, "but we were best friends too, all the way. That's why we won so much.
"You need talent but Kieran (O'Leary) our coach just had it instilled into us that we would always play for each other. We'd fight for every loose ball, keep going until the buzzer in every quarter.
"We won a lot of games that way."
They eclipsed their rivals on Leeside and went head to head with Glanmire in numerous National Cup finals. There were defeats but numerous victories too, with Thornton the MVP more often than not.
"We'd some fierce battles with Glanmire. Danielle (Megan's older sister) had taught us all about it!"
By the same token, respect was always there while the players often linked up in Cork and Irish squads.
"The Brunell years were the best ever, even if sometimes you'd feel so much pressure to do well in the big games."
If that was the case it never showed. Thornton lit up U18 Cup finals in 2012 and 2013, and the U20 grade in 2013, 2014 and 2015, despite not turning 18 until November '15.
Brunell coach Kieran O'Leary was a major influence and so too was Dommie Mullins, the legendary coaching guru in St Vincent's school.
"I'd always look up Dommie when I'm back in Cork. He was such a great coach and you never wanted to let him down."
With Vincent's there was an MVP showing in the top tier second-level U19 A decider and a trip to Cyprus in 2013.
Representing Cork on foreign shores in style. Just like Thornton before her.