Now, at 22, with the West End stage musical Bugsy Malone and TV show Footballers' Wives on her list of credits, Ms Bethan became the youngest-ever day president at Europe's biggest youth event on a frequently showery Bank holiday Monday.
"I started at the Urdd when I was seven but I first won when I was eight for the disco dancing, then the recitation when I was nine. I've done the clog dancing, too, and all the choirs," she says.
"I was meant to start as president at 9.30am but I was late. I was in the opening concert the night before. It's an honour, to be asked to be president for the day."
In leather jacket, jeans and designer sunglasses, she stood out from the grey-suited official crowd. But she teaches dancing for the Urdd twice-weekly in Cardiff, and has been a judge before.
"As president I get to go to things. I watched the drama chairing ceremony.
I've never seen that before and I really enjoyed it."
The daughter of Welsh wrestler Orig Williams, it was Tara's non-Welsh speaking mum who took her to all the competitions.
"It shows that just because you don't speak the language it doesn't mean you are ignorant of it all or that it's an excuse to be, " she said.
And she rushed off to judge the rock and pop bands.