Teachers do not often get to see the fruits of their labour after their students leave school.
The 69-capped international packed down with her former Ysgol Gymraeg Ystalyfera pupil Mel Gnojek at Cardiff Arms Park.
“I feel old, but really proud to see how far she has come on her rugby journey,” said Harries.
Gnojek had been lost to rugby when her mixed team split into girls and boys, and it wasn’t until Harries came to teach at Ystalyfera that she became reacquainted.
“She brought girls’ rugby with her and got me back into the game,” said the 21-year-old.
“I’m thankful for Sioned because without her I wouldn’t be playing today, it’s really special for me to be able to play alongside her.”
Harries recognised Gnojek’s potential from the start and was quick to put her in the “right position”.
“I remember when I first saw her playing, she said to me ‘I’m a 12’, I looked at her straight away and said ‘no, you’re a back rower, you’re a six or an eight’,” she said.
“To see her then develop through the age grades, playing for Seven Sisters and at this level, it’s really nice and humbling.”
Gnojek admitted running out with her coach and mentor against Ireland’s combined provinces team was a “bit scary”, but said Harries “still had her teacher hat on”.
“She was ‘come on Mel, come and do this with me’,” said Gnojek.
“She’s amazing isn’t she? So determined and strong.
“Everyone can see it, not just our team, the teams she plays against. Everyone is frightened of her – but in a good way.”
It is not only on the rugby pitch where Gnojek has followed in Harries’ footsteps, as the pair are now colleagues at Ysgol Gymraeg Ystalyfera.
Gnojek co-captained Wales’ emerging squad which beat England in 2018 and 2019, but has yet to win a senior cap.
Her chance could come in the 2023 Women’s Six Nations, and there will be no prouder mentor than Harries should that happen.