McCallion’s father Seamus was a try scorer for Halifax when they beat Saints at Wembley in 1987 and was Rhinos’ physio 12 years later in their record-breaking men’s Challenge Cup final win over London Broncos.
She said: “It is kind of crazy that he played for Halifax against Saints and I am here 35 years later, playing against Saints in a Challenge Cup final as well.
“If I get the chance to play it will be the biggest achievement I’ve ever had and it will be massive for my dad.
“He has been backing me all the way and he is really, really happy about it.”
Seamus now runs a physiotherapy clinic in the Newcastle area along with Orla’s mum Lesley - who also had a spell on Rhinos’ backroom staff in the 1990s - and brother Aidan.
“They are still huge fans of the club,” Orla said of her parents.
“They have been at every game and backing us all the way so it is going to be really exciting for them.”
Orla, 21, was born in Leeds, but grew up in the north east and played both union and league for local clubs before joining Rhinos’ academy.
She made her debut in 2019 and started in last year’s Betfred Women’s Super League Grand Final defeat by Saints, but - if selected - today will be her first Challenge Cup decider.
“I am buzzing, everyone’s very up for it,” McCallion said.
“We are very excited to get at Saints again after last October.
“In the Grand Final we had a great first 20 minutes, we really rocked Saints, but we have had a change of personnel since then; we’ve had a few additions and people back from injury which has really strengthened our squad.
“That’s why we are backing ourselves even more, we know what we did in October and what we can do better this time around.
“A lot of people have got a lot of fire in their bellies about losing the Grand Final and the Challenge Cup trophy.
“Quite a lot of players who won that in 2019 want to prove themselves this year and there’s others who want to get it for the first time.”
Today’s decider will be broadcast live on BBC2 as the first part of an Elland Road triple-header also featuring both men’s semi-finals.
It will be one of this country’s biggest occasions for women’s rugby league and McCallion said: “It’s huge, especially with having the men’s games on.
“Hopefully that will bring some more people down to watch and they’ll be able to see what we do and how well we play.
“It is huge for the sport and hopefully it keeps growing and growing, which is what everyone wants.
“I have never played in a stadium like that before, so it’ll be great.
“It is a huge occasion, everyone’s going to be nervous, but the thing that’s new for me, with this squad, is I have never been able to back every single player I am playing alongside as much as this.
“That means you’re not nervous about missing a tackle of individual things.
“You back the people around you and that changes your outlook on the game.”