Hilary Duff‘s got a great helper in her son — but the protective big brother might be taking it a little far.
In an interview with PEOPLE on Sunday at the Happy Little Camper + Veeda launch party, the musician and Younger actress opened up about how her 7½-year-old, Luca Cruz, has been keeping an extra close eye lately on his baby sister Banks Violet, 1, to the point where he’s scolding his mom!
“He doesn’t want her to ever fall off the couch … sometimes I’m like, ‘I swear I’m a good mom,’ ” Duff, 32, said at the event, which was held at her home in Beverly Hills, California, and also attended by Jamie-Lynn Sigler and her son Jack Adam, 21 months.
“He’s like, ‘Well, you need to watch her,’ ” she continued in her conversation with PEOPLE. “I’m like, ‘She’s gonna fall down. She’s got to learn not to go near that’ or whatever. I sat him down once and said, ‘Hey, you survived and I was your mom, so I swear she’s going to be okay.’ “
Despite Luca’s eagle eye, “He will not change the diaper,” Duff — who wore Lisou for the launch party — said of her older child, whom she shares with ex Mike Comrie. (Banks is her only child with fiancé Matthew Koma). “But he’s very helpful and he’s just on top of her.”
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The Lizzie McGuire star praised her “amazing” son for being such a caring, kindhearted individual, noting that she is especially impressed with his demeanor given his young age.
“He’s the sweetest kid,” she said of Luca. “He’s getting very thoughtful … if someone gets hurt, he’s like, ‘Oh no, are you okay?’ And that’s a learned thing for kids; it’s not just naturally in them. So it’s really cool to watch him become very aware and conscious and kind.”
“It’s crazy to watch all the things happen where it’s clicking — all these things we’ve been pounding [into] him since kindergarten and first grade,” Duff added. “It’s finally clicked where he just thinks of things right off the bat, or he’ll problem solve. It’s really amazing.”
RELATED VIDEO: Hilary Duff Says Son Luca “Thinks I’m Cool Now” amid Lizzie McGuire Reboot News
As for Banks’ latest milestones, “She just started walking” and can mimic “a bunch of animal sounds,” the proud mom shared with PEOPLE of her “interactive” daughter, who also has six teeth now.
“She loves scrambled eggs. She loves fruit — she eats tons of fruit,” Duff said. “She won’t eat purees anymore. I think since she got her teeth, she thinks she’s too good for purees. So we have to steam her veggies down.”
“She’s definitely a carb queen. She loves that bread,” the star joked. “She loves smoothies. I’ve actually started putting vegan protein powder in her smoothies because she won’t eat a lot of meat, so we’re trying to find sneaky ways to get her protein.”
The actress and singer is proud to partner with Happy Little Camper, which she told PEOPLE felt like “a really natural” fit since she loved their natural diapers to begin with.
“I bought everything that was on the market and when I tried Happy Little Campers, they were my favorite fit. Then the functionality of them was the best for me,” Duff said. “So I was just ordering them and became a little bit of an unofficial ambassador, just in my moms circle, of like, ‘You have to try these. They’re amazing.’ “
Not only is she a fan of the diapers, but the “all natural” wipes and feminine-care products, too, the mother of two shared with PEOPLE.
“I had been using the same products for years and I was like, ‘Oh, I’m busting my ass to like make sure my kids are getting all the best stuff. I should probably make a change myself and think about doing the best for my body too,’ ” Duff said.