If he wanted to play rugby, his mother told him, he would have to make a living out of it. For families in Newtown, one of the poorest districts on the outskirts Suva, the Fijian capital, rugby boots are expensive.
Raised in a one-room house with corrugated iron walls, Tuwai's family home is modest. But today, to the people of Newtown, the Fiji star represents hope.
"All the children, when they play games, they want to be like Jerry. He's setting a standard for them. He doesn't drink, doesn't smoke; the children want to follow in his footsteps."
Tuwai, who used to play rugby with plastic bottles and bundled-up T-shirts on the streets of Newtown, is now a world champion, Olympic champion and, most recently, captain of Fiji's sevens side.
Understandably, his family are proud. When her son was first selected for the national team, Vualiku cried.
"I was so overwhelmed with happiness," she explains. "I knew I wouldn't worry about food, about clothes. And Jerry did that for us; for me, my husband and my children."
"It's not me, it's not my husband. It's God. Because I know I didn't dream that one day Jerry will be a superstar, a rugby player like this. It was all in God's plan."
Tuwai has himself admitted that he was once close to falling onto a troubled path. But rugby, which he only took up after dropping volleyball aged 18, has provided an answer.
A diminutive figure at 5'7", the first jersey Tuwai wore for a local team flapped around his knees. What he lacked in size, he made up for with fast feet and lightning speed, jinking past defenders without so much as a hand being laid on him.
Now aged 29, Tuwai has made 200 appearances and scored 92 tries in the HSBC Sevens World Series, captaining Fiji since 2017.
There's one career accolade, though, that the family holds dear.
When he's travelling with the team, Tuwai takes his Olympic gold medal with him in his suitcase -- the first and only medal of any kind that Fiji has won at the Games. But when he's back home, the family can proudly display it to friends and neighbors.
"People who were sitting in wheelchairs, sick men and women in beds -- I took it all round the community," Vualiku recalls after her son had returned from Rio.
"I took it all around the village. I started in the morning from one side of the village, came home for lunch, then took it up and started from the top of the village."
The Olympic aftermath was a moment that saw Fiji rejoice and Suva become a cacophony of noise as locals sang songs and thumped spoons against pots.
"I went to my neighbor and asked if I could borrow her 40-gallon drum," says Vualiku. "I led all the children, the mothers, everybody round the roads with the big drum. Everyone came out."
It's a fervor that has long gripped the Pacific Island nation when its team takes the field. In good weather, Vualiku takes the family television onto the streets to cheer her son from the other side of the world.
But for all his success -- be it the silverware won or the clamor of support back home -- the local hero has never forgotten home.
"The same Jerry I brought up, the same Jerry that went to New York or Hong Kong, has come back the same Jerry. He's never changed," says Vualiku.
Idolized back home in Suva, Tuwai also commands respect amongst his players.
The side he's captaining currently holds a slender lead at the top of the Sevens World Series leaderboard, chasing a third title in four years with two tournaments remaining on the calendar.
"He's my little genius," Gareth Baber, who took charge of the side after the Olympics, tells CNN World Rugby.
"You can see how much he puts his body on the line. You've got to have ultimate respect for it. It's all very well being 6'6" and 120-odd kilos, but when you're his size and you're still smashing people around like he does -- then that commands respect."
Not the loudest man in the squad, some questioned Baber's decision to select Tuwai as captain. But, explains the Welshman, "when Jerry speaks, everybody listens.
"He's not a shouter, he doesn't scream and shout and demand things -- there's other players that I task with that," adds Baber. "What Jerry provides is a real consistent, rational approach to the game.
"When he comes away [from the field], he is the most humble player. He's the first one with the opposition, win or lose, to go up and shake your hand and say, 'good game.'
"The values that he has as a human being and his behavior is exactly what I want my team to look like."
Humility motivated Tuwai when he laced up his first ever pair of rugby boots a decade ago.
It was there when, at the start of his career, he bought a washing machine for his family, and it's there when the final whistle blows on a rugby match thousands of miles from home.
His mother's words ring true. Jerry's never changed.