England captain Katy Mclean says New Zealand's World Cup group defeat by Ireland is evidence the Black Ferns have lost some of their invincibility.
The loss was New Zealand's first at a World Cup since 1991's semi-finals and also follows England's five Test victories in nine meetings since 2010.
"Ireland beating New Zealand is massive for us," Mclean told BBC Newcastle.
"Since 2010, we've played them nine times and they don't have that hold they used to have."
Mclean continued: "It'll make a massive difference if and when we play them, we just need to worry about Canada first."
|How do the knockout stages work|
|The four semi-finalists will be the top three group winners and the second-placed team with the most points.||The remaining eight clubs then play for the remaining rankings 5-12, with 5-8 and 9-12 ranked teams split.|
The Red Rose ladies have won their first two games, beating Samoa and Spain comfortably, but have a final pool-stage match against Canada on Sunday to decide a semi-final place.
"Undoubtedly, all the games we've ever played against Canada have been tough, physical, quick tests," Mclean added.
"We are lucky our coaches and analysis teams do a lot of work on the details like scrums and line-outs.
"It's easy for us to go in and pick up on things."
There has been support from England's male counterparts going into and during the tournament, as Mclean and her team-mates seek to end a run of three consecutive losing finals in this competition.
"We've been really lucky to have Stuart Lancaster in before we left to come to France and have had loads of messages and tweets from the guys," she added.
"It's all one big England family."