Jim Edmonds' Fiancée Kortnie Opens Up About the 'Challenge' of Becoming a Stepmom

Jim Edmonds/Instagram Kortnie O'Connor and Jim Edmonds

Parenting is never easy — and for Jim Edmonds' fiancée Kortnie O'Connor, it involves stepping in to help raise her future husband's children.

Speaking to PEOPLE exclusively, the engaged couple — who are set to wed in Italy on Sept. 25 — spoke about how they've come together as a parental unit. O'Connor, specifically, opened up about her experiences of coming into a stepparenting role.

"In the beginning, it was a little bit of a challenge because it was so fresh, and I didn't really know how I wanted to present myself to them," says O'Conner, who got engaged to Edmonds, 51, last August.

"I let things happen naturally, and let them get to know me and feel comfortable with me first," she continues. "I didn't want to put on them my values or what I want them to think I am, and have them calling me mom. I didn't want to push anything like that on them at first. So I just let things flow naturally and then develop into a really great relationship."

O'Connor says she feels this approach has "worked out really well" for everyone.

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"I feel like we have this bond between us, but it's not, 'I'm your mom,' 'I'm your new mom,' or 'I'm your stepmom.' It's just we're really good friends," she says. "We have fun together. They trust me. I trust them. We have a great, open communication type relationship. So that's what I wanted to be with them, instead of jumping right in and being like, 'I'm going to be your stepmom.' "

O'Connor adds that Edmonds' children are "really awesome" and have "been really fun to get to know and play with."

Edmonds has seven kids from his three previous marriages. Addressing how O'Connor has stepped up to the task of parenting, the former pro baseball player says she "does a great job."

"I think handling it the way she handled it was pretty good because a lot of people try to push themselves onto kids. And it's been really seamless," he says. "There's been a lot of challenges for both of us [with] raising children, but I think it's been amazing. It seems like it just gets better each day."

Edmonds also pointed out how O'Connor is "especially" great with his youngest kids, one of which — Hart, 4 — was diagnosed with a condition that impacts brain tissue.

Kortnie O'Connor/Instagram Jim Edmonds with Kortnie O'Connor and his children Hart, Hayes, and Aspen

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"It was always, 'Daddy, Daddy, Daddy.' And now, it's 'Kortnie, Kortnie, Kortnie,' " he continues. "Like I said, it just grew into this really nice relationship that we have as this little family when they're with us. And it's been a lot of fun, and it gets better each day."

Giving an update on Hart, specifically, Edmonds says his son is "doing good."

"I thought it was going to be a massive issue. But from what I see, he's just behind — he eventually catches up to everything that his [twin] brother [Hayes] does," he says. "It was four to six months late, his walking, his coordination. He's a little edgy still, but he is catching up."

"As far as running around the house and doing the things that little boys do, he's just a little bit behind his brother," he continues. "He's come a long way, a lot further than I thought he would already. It's fun to watch him grow."