"As soon as he walks into the ring, I'm like 'okay, now is the time to put in what you've learned throughout the camp'," she told the Herald. "I watch closely his progress, whether it's progress going forward, or if it's a bit slack. I can tell whether he was honest with his training or if he's been a bit slack."
Boxing is in the families of both Sala and Dempsey, who were friends in Samoa and became a couple in 1988, a year after they arrived in New Zealand. Their daughter Elizabeth was born in 1990. Dempsey, a machine operator who still works fulltime, used to buy his boys Joseph and John boxing gloves or punching bags each Christmas.
When other kids would be playing with their new tennis rackets or volleyballs, the Parker boys would be hitting the heavy bag in front of their uncles and aunties, with Dempsey, named after American heavyweight great Jack Dempsey, insisting they would be world champions.
And while Sala doesn't profess to be be a boxing expert, she knows her eldest son.
"I said after the [Carlos] Takam fight [in October for the IBF mandatory, a tough win for Parker]; 'what was wrong with you?'. He sometimes denies my questions. 'What were you up to?'. He said, 'one of those days, mum, it's not going to happen again'."
Sala and Dempsey still live in the Papatoetoe home they bought before their three children were born, and it was here, in a place which now boasts Joseph's seven professional boxing belts in a cabinet on a wall, that the Parker boys watched the likes of Mike Tyson and David Tua on television and kindled their love of the fight game.
It was here too that Sala handed down a request to Joseph which he has followed to this day.
"I watched and thought 'why is the winner jumping up and down when his opponent is on the ground?'. That's somebody's son and I'm sure that's somebody's dad. That's someone's brother. If you're on the ground and this person is jumping up and down, how is your family going to feel?'.
"I think Joseph was 15 at the time and I said 'you know what, I don't really like this thing'. I explained it to him: 'it's not a good look'.
"I said to him 'please son, if you win the fight, don't jump. Just thank God that you've won the fight and respect the referee; let him raise your hand for you, that's what he gets paid to do - to ensure your safety and raise your hand if you win.
"It's something he still upholds. It's a sport; at the end of the day you have to respect that person as a human being. Joe said when he was 18, 'okay mum, I'll listen to you. If the ref raises my hand, that's fine, but let me assure you, if I win the world title, mum I'm going to raise my two hands'. I said, 'yeah, and I will raise my two hands too'."
And if Parker does raise his two hands to become the first New Zealand-born fighter to win a significant heavyweight world title belt, there will be joy, but there will also be relief. And above all, perspective will be kept.
"We don't do big celebrations," Sala said.
"We keep it low key. We just appreciate the kids... for the 21 fights he's had so far, there have been no celebrations. We just go home, thank God he's safe, and that's it."
