All 28 members of the U.S. 2015 World Cup winning squad have filed a lawsuit against their national federation, complaining about wages and working conditions compared to the men's side, who failed to qualify for the 2018 World Cup.
"You look at the U.S. team and they're a lot more successful than the men's and that's their argument. So first and foremost England need to be more successful," Duggan said
"I can't sit here and say we're going to get to that stage, we need to be putting trophies on the table. Hopefully one day we'll be like that, but fair play to the U.S. team because it (equal pay) is what they deserve."
Duggan was part of the England side which reached the World Cup semi-finals in 2015 and the last four of the 2017 European Championships.
After the Lionesses piped the U.S. to win the four-nation SheBelieves Cup in March, she challenged the team to take the next step and go all the way in this year's World Cup in France.
"I believe we can, we've got to two semi-finals at major tournaments, we've beat all the tough opponents. So it's possible but it's OK saying it, it's about doing it," Duggan said.
She is also confident her side will be able to continue the feel-good factor Gareth Southgate's men's side provided back home with their run to the last four in Russia, which she said began with the women's excellent 2015 World Cup campaign.
"To be honest, we started it, we had amazing support in Canada and Gareth followed on from that, great credit to him because he got them playing nice football and people wanted to be part of supporting England again," she said.
"There was a dip in the past few years but the buzz is back and I'm sure everyone will be behind us this summer."
Former Manchester United and Everton player Phil Neville had no experience of the women's game when he succeeded Mark Sampson as England coach last year but Duggan praised the impact he has had on the team.
"We need people like Phil who have experienced winning trophies to share that experience with us," she said. "The standards he sets are important to him, everyone's enjoying life under him and the new style we play, hopefully we can see that in the summer."
