Nicky Hilton Says She and Her Siblings Are 'Constantly Asking' Each Other for Parenting Advice (Exclusive)

Nicky Hilton Rothschild is loving life as a mom of three.

The fashion designer, 40, recently took a trip to Universal Studios Hollywood to celebrate the launch of exclusive new Gabby's Dollhouse merchandise at the Animation Studio Store. She was joined at the celebration by daughter Theodora "Teddy" Marilyn, 6.

Teddy wore apparel from the newly launched line, which includes exclusive cat ear headbands, apparel, accessories, and more. Mother and daughter even got to take some photos with Gabby herself before enjoying the rest of their day at the theme park. 

Hilton Rothschild tells PEOPLE that her girls have been fans of the hit preschool show since the beginning.

"My girls have been watching it for what feels like forever. They just love it, and I am a crazy cat lady, so I think my girls have definitely inherited that gene," she laughs. "So they love Gabby and her cats, and they're little mini crazy cat ladies, too."

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The model's three children with husband James Rothschild — Teddy and Lily-Grace Victoria, 7½, as well as 20-month-old son Chasen — are all at different stages, but the mom is having a blast keeping up with all three.

"My older one is very into rock climbing. She loves going rock climbing. And the little one Teddy, she's a little girlier," Hilton Rothschild shares.

"She loves dressing up. She loves costumes and makeup. She's very excited to wear her Gabby's Dollhouse cat ears to the event. She goes to a private school, so she wears a uniform every day and she's always putting on cat ears or some other crazy accessory."

As for her little guy, he's got the hang of walking and is ready to talk.

"He's been walking for a while and now he's trying to talk. It's lots of gibberish, but it's sweet. He's a handful, but he really loves his big sisters. He likes to come in and terrorize their room a little bit," she shares. "He can annoy them, but they're good about it."

When it comes to keeping their brood entertained, Hilton Rothschild and her husband either go at it together or divide and conquer.

"More recently, I find my husband and I will split duties. So he'll take the girls to do something and I'll take my son, or vice versa, because there is that gap right now. It'll be a while until my not-yet-2-year-old enjoys the Museum of Ice Cream," she laughs.

The family enjoys a lot of time traveling together and likes to get in on the fun with Hilton Rothschild's extended family.

"One of my favorite trips I've ever taken was to Maui. I did it with my sister, her husband, her baby, my husband, and all my kids. It was our first family trip. We stayed at the Grand Wailea, which Paris and I grew up going to. It's that hotel with all the water slides and the lazy river and it was just the most fun, special bonding vacation. I love Hawaii. That is my happy place."

The kids also like shorter trips like their many visits to see family in Los Angeles.

"They definitely loved Maui, but they love coming to L.A. It's one of their favorite places because we stay at my parents' house and my mom has built this nursery/children's room. So they have all their toys and their bed and they get to see all their cousins."

The designer says she's cherishing this time of growth in her family, which has given her a new and exciting way of bonding with her siblings.

"It's so funny because I just got off the phone with my brother, who has a days-old baby at home," she shares. "We're constantly asking each other for advice—on diapers, baby carriers, baby classes. It's a whole different ball game."

Hilton Rothschild looks forward to getting in more family time throughout the spring.

"I love all the holidays, Easter being one of them. I'm one of those moms who starts decorating the Easter baskets and collecting stuff for it months in advance, so I'm looking forward to Easter."

Fans can shop an exciting assortment of Gabby's Dollhouse goodies that includes Spin Master’s award-winning Gabby’s Purrfect Dollhouse and deluxe room sets, alongside all-new, exclusive cat ear headbands, plush, apparel, accessories and more that are only available at Universal Studios Hollywood and Universal CityWalk.