Hilary Duff’s 6-year-old sonLuca Cruzis handling the birth of his sister,Banks Violet, so well that the new mom of two sometimes creates her own chaos.

At last Monday’s kickoff for the Disney store andshopDisneyToys for Tots holiday campaign — which donates gifts to kids whose parents cannot afford to buy any — theYoungerstar, 31, talked about her growing family and the holidays.

“Well… Everything has been flipped upside down,” the actress exclusively tells PEOPLE of her life since welcoming Banks on Oct. 25.

Vivien Killilea/Getty

Hilary Duff Kicks off the Disney store and shopDisney’s Toys for Tots Holiday Campaign

Hilary Duff Kicks off the Disney store and shopDisney’s Toys for Tots Holiday Campaign

She continues, explaining how Luca is handling everything:

“Honestly, I thought it was going to be a huge adjustment, but he kind of acts like she’s always been here. It’s really sweet!” she says before revealing his preferred way to bond with his sister.

“One of his favorite things is skin-to-skin before bath time, and he loves to pinch her cheeks — which is funny because he hated when anyone did that to him. I think he finds her edible,” she adds. “My favorite thing to do with him … [is] chase him around with dirty diapers.”

Hilary Duff.Vivien Killilea/Getty

Hilary Duff Kicks off the Disney store and shopDisney’s Toys for Tots Holiday Campaign

Duff also says that her gang will be going on their first family vacation this year — “We’re looking forward to a non-traditional Christmas, swimming and chilling in the sun!” she reveals.

It’s a big change of pace from how Duff used to spend the holidays when she was a kid.

“Growing up, my mom made it a point for us to help at a food drive, especially on Thanksgiving,” the Disney Channel alum recalls. “Since having kids of my own, I haven’t done it in a while, but I would like to start the tradition again now that Luca is a bit older.”

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Duff adds that the only thing she’s asking for this year is “anything from Mileno Silvano — pillow, coat, I won’t be picky!”

Based on the “Come Clean” singer’s social media, the family of four, which also includes her boyfriend and Banks’ fatherMatthew Koma, is already an adorably tight-knit unit.

Duff posted a picture of them on Instagram that shows herself and Luca sticking out their tongues as the dad of one flaunts his new pink hair. (Luca’s dad is Duff’s ex-husband, Mike Comrie.)

Meanwhile, Banks quietly rests in her parents’ arms. “Banks … you gotta try harder,” the new mom teased in the image’s caption.

Between Nov. 29 and Dec. 15,the Disney store and ShopDisneywill donate $5 to Toys for Tots (up to $1 million) for every new, unwrapped toy donated at a Disney store in the U.S. or online.

source: people.com