Banyana Banyana lost all three games on their debut World Cup appearance under Ellis four years ago in France, and were unlucky in their opening match at this year's tournament, taking the lead against Sweden only to go down 2-1 after conceding the decisive goal in the 90th minute.
"It might be our second World Cup, but I think this team has matured so much over the last four years," Ellis said at a pre-match press conference on Thursday in Dunedin, where South Africa will face Argentina in their second game in Group G.
"This team has got so much better mentally as well, with all the challenges that we faced."
South Africa came into this World Cup after winning the Africa Cup of Nations for the first time in their history last year, despite losing star player Thembi Kgatlana to injury and facing a Covid outbreak in their camp.
"At the last WAFCON we lost Thembi, and a lot of South Africans went into shock, but we had a plan," Ellis added.
"This team has really fought through adversity, through challenges, and against Sweden the same thing.
![South Africa's average positions v Sweden South Africa's average positions v Sweden](https://livesport-ott-images.ssl.cdn.cra.cz/r900xfq60/6f8155aa-bc62-4879-869b-7468360ffec1.jpg)
"We are not used to playing in torrential rain, it is not what we are used to back home, but I think we were brave, courageous, and I think we stood up.
"Even though we lost, people saw the South African team, but I think there is more that people haven't seen and hopefully we can showcase that tomorrow."
Like South Africa, Argentina are also looking for their first-ever Women's World Cup win after losing their opening game 1-0 to Italy.
Whoever loses could be eliminated on Saturday, depending on the outcome of the other Group G game between Sweden and Italy.
"This is more than just historic, it is a game we must win," Ellis said.
"It is our final, we can't look any further ahead than that game because everything else doesn't matter.
"It will give us an opportunity to try to get into the next stage and that is ultimately what we wanted to do before we came here."