James was one of the best players in the tournament in the group stage but missed England's last two matches after receiving a red card for stamping on an opponent in the last 16 match against Nigeria.
Hayes, whose Chelsea team also includes England defenders Millie Bright and Jess Carter, said she had been in touch with James and confirmed the player was excited to be in the frame for selection on Sunday.
"Lauren is an outstanding player and will go on to contribute many more moments for both club and country," she told reporters in Sydney.
"As always, she will be reflective and she's moved forward from (the red card) and she's very excited to be available for the final.
"Those players are prepared for whatever happens, whatever team (coach) Sarina (Wiegman) picks, I'm sure Lauren will be ready."
Hayes said Wiegman had provided the leader that a "golden generation" of England players needed to fulfil their potential on the global stage, and was certain they would all be prepared for Sunday.
"It's what they've trained for for years ... delivering the job under pressure," she added.
"England have amazing leaders, it's not just Millie Bright, it's across the team. Mary Earps, Lucy Bronze, Alex Greenwood, Keira Walsh, Rachel Daly.
"There's senior players there that know how to deliver on all fronts, and collectively as a team. They're ready."
Hayes said she would be backing England to claim a first world title on Sunday but did not think it would be easy.
"I think Spain will try to pin England into a five back so that tactical battle will be interesting," she said.
"I think England have the pace, the power, the attacking threats to cause problem but in (Aitana) Bonmati and (Salma) Paralluelo Spain have players who are of the highest level. For me, the two best teams are in the final.
"I'm English and I want our country to win."
With Vlatko Andonovski having resigned as U.S. coach on Thursday after the early exit from the World Cup of the double defending champions, Hayes was asked whether she was interested in the job.
"I'm very happy at Chelsea, I've made that clear," she said.
"I've been there for 11 years, it's my home. I think the U.S. has most wonderful players. Perhaps the tournament didn't go the way that they wanted, but my focus is on getting home and preparing the team for the start of the season."
