Kaia Parnaby started playing softball by tagging along to her younger sister’s practices.

This time, Parnaby’s experience in Hawaii helped convince little sister to follow her to Manoa.

Parnaby will have some familiar company on the Rainbow Wahine roster next season when Lauren Parnaby, who signed a National Letter of Intent this week, joins the program as a catcher/outfielder.

“That’s really exciting, I love pitching to my sister at home,” said Kaia Parnaby, part of a UH pitching staff that ranks among the nation’s stingiest.

“When she came to the (Women’s College) World Series last year, it was obvious where she wanted to be.”

Lauren Parnaby’s addition will add to the list of Australians to come through the UH program, a group Kaia joined last year when she helped the Wahine advance to Oklahoma City as a freshman.

Now a sophomore, she worked through some early-season elbow issues to ascend the national statistical rankings while providing a strong left-handed complement to junior righty Stephanie Ricketts.

The Wahine (30-13, 8-4 WAC) enter tonight’s opener of a key Western Athletic Conference series with third-place Boise State (26-15, 9-3) seventh among Division I teams in earned-run average at 1.40. Parnaby ranks ninth in the country and first in the WAC at 0.99.

In five league appearances, she’s 3-1 with a save and an ERA of 0.51. She earned WAC pitcher-of-the-week honors after last week’s shutout of Louisiana Tech.

Parnaby (11-3), who has four shutouts this season, typically pitches the middle game of a series, with Ricketts (18-10, 1.57) throwing the opener and finale. The arrangement has helped keep her fresh heading into the late stages of the season following a rigorous offseason.

After throwing in UH’s season-ending loss to Arizona in the WCWS last June, Parnaby met up with the Australian national team and pitched in the world championships in Caracas, Venezuela later that month.

“I think everything beginning from postseason really helped me,” Parnaby said. “From pitching against the tough Alabama lineup to UCLA to Arizona, then going to face Team USA and Team Canada and Team Japan, facing the best hitters in the world, it helped me coming into this season to be a tough pitcher.”

But a heavy workload in the national championships in Australia during UH’s winter break left her arm-weary when she returned this spring. UH coach Bob Coolen shut her down for five weeks before the season, but she still felt discomfort in her elbow that limited her innings early on. Her elbow improved with assistance from the UH training staff, and she’s gotten sharper as the season has progressed, following the pattern of many of her games.

Coolen said Parnaby’s demeanor tends to be pretty loose, “then all of a sudden she pops it, and you’re like, ‘Where did that come from?’”

“Once the game starts going, her ball moves a lot more. Second time through (the order), she knows she has to be better at it. Third time through, she really picks it up. She knows certain hitters are looking for certain pitches.”

That perceptiveness comes despite a relatively late start in the sport. It was at one of Lauren’s practices when a coach spotted 13-year-old Kaia and thought she might have the build to pitch. A week later she was taking individual lessons, and a couple of years later she was representing Australia in the junior world championships.

That’s when she first worked with former UH great Brooke Wilkins, the team’s pitching coach. The UH connections continued when she joined a national team that included Stacey Porter, Clare Warwick and Justine Smethurst, all of whom left lasting marks on the Wahine program.

When Parnaby started looking at colleges, “(Hawaii) was the top of the list because it had so many Australians I played with and looked up to.”

Now she finds herself on the other end of that scenario with Lauren coming to join her in August.

“It was a big moment for the family to have both of us here,” she said.