The other finalists are Australia's Charlotte Caslick and Russia's Nadezhda Kudinova.
But there was no place for Ghislaine Landry, who led the Women's Seven Series in scoring with 301 points this season and was second in tries (39) behind Portman's 52, or fellow Canadians Ashley Steacy and Karen Paquin. Both Steacy and Paquin were named to the Sevens Series' Dream Team for the 2014-15 season.
Canadian coach John Tait said different players had stepped up for his team during the season, sharing the limelight.
"I'm glad Ghislaine got recognized as the top points-scorer for the year," Tait said Thursday from Victoria. "I'm surprised she wasn't in there as a nomination."
Tait was not allowed to nominate players from his own team for the award.
The five-foot-two Steacy is a key player for the Canadians. "I think she's one of the best defensive players, one of the best tacklers in women's rugby, period," said Tait.
With blistering speed, Paquin left more than a few opponents in her tracks in scoring 22 tries.
Goss led the Kiwis to four tournament wins and their third overall title in a row. Woodman scored 52 tries in the six-event series, the first woman and only fifth player in Sevens World Series history to pass a half-century.
Kudinova scored 149 points for Russia while Caslick, who turned 20 in March, helped the Australians reach four finals in 2014-15. Caslick was shortlisted for the award last year.
The winner will be announced at the World Rugby Awards dinner in London on Nov. 1, as chosen by an independent awards panel that includes a representative from each of the teams on the series, the World Rugby Sevens referee manager Paddy O'Brien and the Series television commentators.
Emilee Cherry of Australia won the award in 2014 while New Zealand's Kayla McAlister was the winner in 2013.
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