The current captain of the Wallaroos, the reigning Super W player of the year, Hamilton, along with her family, lives and breathes the game.

So if someone had told her at the start of the year she'd be preparing to play in a rugby league - you know, that other code - grand final, she'd have very nearly hit you harder than she does the Black Ferns.

"I would have said 'definitely not'," Hamilton laughed.

The 28-year-old rugby union back-rower will come off the bench in Sunday's NRLW decider at ANZ Stadium, the Panuara product set to add plenty of big-game experience and strength to the Sydney Roosters' pack.

This cameo in Roosters colours is Hamilton's first foray into the 13-man code.

"I've enjoyed it," she said.

"It's not as competitive as rugby union, in the sense every tackle you're competing for the ball, but I've really enjoyed the environment I've been in and the team we have. It's been fun. I've played with a lot of the girls in union in the past."

The Roosters will tackle the two-time defending NRLW premiers, the Broncos, in Sunday's grand final.

Hamilton says despite the Broncos only losing one game in three seasons her side was heading into the game confident of inflicting the Brisbane girls with their second loss.

"A lot of these girls in the team are experienced players in their own right, big games bring out the best in people and we just need to understand that," she said.

"I don't think we've peaked as a team yet. We can do better. I definitely think we can do this."

Hamilton is one of a handful of the country's best rugby union players to appear in the NRLW this season, with COVID-19 putting a halt to the international calendar for the union girls.

She said transitioning from a rugby union backrower to rugby league prop was tricky, but Roosters coach Jamie Feeney is keeping it simple for Hamilton.

"I don't want to over-do it, which being a backrower in union you need to do. You do a lot. Playing in the middle in rugby league, you just have to do your job," she added, saying her job is to "dominate the contact and not get off the tackle so quickly".

"I just have to try and slow things down a bit too, and get the ball in my hands and run hard. I'm excited."

Orange Hawks pair Vanessa Foliaki and Kaitlyn Phillips are also part of the Roosters' NRLW squad for the grand final.

Foliaki will start in the second-row, while Phillips is in the extended bench.

Kick-off is at 4.05pm on Sunday.