New mom Mila Kunis has been busy promoting her new film Jupiter Ascending, which premiered in Los Angeles on Monday (February 2). The actress, 31, looked lovely in a black bustier Dolce & Gabbana dress featuring a full-skirt, paired with lacy Christian Louboutin stilettos.

When asked about the most surprising aspect of motherhood, Kunis had no hesitation. “How little any of this matters,” she told Us, gesturing to the showbiz glitz around her movie release. “Not to say that this is meaningless. But like truly how little this matters and how much I’d rather be home right now.”

The following night, during an appearance on Jimmy Kimmel Live, Kunis dished on leaving her daughter Wyatt Isabelle, whom she welcomed with Ashton Kutcher on Sept. 30.

“It’s really weird to be out,” she shared. “This is my very first time out and about. Swear to God! I left [Wyatt] at home yesterday for the first time during the premiere. It’s frightening. I have to be honest. I was with her every day for the first four months of her little life. I cried. I did. It’s weird. It’s very strange. If anyone’s a mom, and being a stay-at-home mom, it’s a very weird feeling to all of a sudden leave your child.”

She added: “It’s not that I don’t trust who she’s with. It’s just the idea of not being with her.”

When Kimmel joked that she doesn’t trust Kutcher to take care of their daughter, Kunis replied, “I trust him! He’s an incredible father! But the way that I hold the baby and the way that he holds the baby…I mean, he’s like a jungle gym!”

As for losing the baby weight, Kunis said, “Breastfeeding is like working out.” She added, “I am very active. I hike almost every day with her. I strap her in a papoose and away we go.”

Kunis and Kutcher are not using a nanny, but her mother has been helping out.

“I was cloth-diapered,” Kunis shared. “In Russia, 31 years ago, they didn’t have the current-day diapers. Everything was cloth, which means you sanitize them in a hot bucket, you dry them, you iron them, you hang them, you pin them, and that’s how I was raised. When I showed my mom diapers—current diapers, with Velcros and Elmos on them—she was like, ‘I don’t understand what this is. What do I do?’ I was like, ‘Mommy, you lift the baby up, stick it under and Velcro.’ ‘And then just throw in the trash?’ I was like, ‘Away it goes!’ And she was like, ‘Well, if I had this, I would just have seven babies. This is amazing.’ But, literally, it took her the longest time to stop putting it upside down. Like, she would put the Velcro on top and I was like, ‘No, no, no! On the bottom!’ Like, she will cloth-diaper the baby—any baby!—but these Velcro things really got her. Very different. Very, very different.”

And it sounds like her father is fairly excited as well.

“My dad has gone crazy buying her things! Like her very first cell phone and the piano kicker and the Baby Einstein Imaginarium,” Kunis shared. “My house is just filed with noise.”

That said, baby Wyatt “likes rope and string. She doesn’t really care about anything else.”

Kunis went on to talk about Kutcher’s ongoing app developments.

“People bring more baby things to him, and he kind of just runs them by me. Like, there’s these things called Bellabies—I’m not doing an advertisement for anything, by the way!—but you put the little microphone around the belly and you can hear the baby’s heartbeat,” she shared. “I think this is awful because unless you know what you’re doing, you may not hear the baby’s heartbeat and then panic ensues. It’s like WebMD but bad. If your baby’s like 7 months, you’ll hear it anywhere. But if your baby’s a little poppy seed, you really have to dig for it. Like, you gotta find that baby heartbeat,” she said. “And let me tell you, at 3 months I was like, ‘Where is it?!’”

She added: “People run these things by him all the time. Listen, when we started dating—this is an awesome story and this is fact!—Tinder hadn’t really been out yet. And he was like, ‘So, babe, I got this thing that I’ve been thinking about. You need to do me a favor and download this app.’ I was like, ‘No problem.’ I download Tinder, OK? I was like, ‘What is this?’ Like, swiping things left and right. I was like, ‘This is amazing!’ This is stuff that I do at home. He makes me go on all of these websites. Everything!”