Hilary Duff has a "big connection" to her mom friends.

The 37-year-old star is close to the likes of Ashley Tisdale, Meghan Trainor and Mandy Moore, and Hilary has admitted that she appreciates being able to lean on them for support "all the time".

Hilary - who has Banks, six, Mae, three, and Townes, six months, with husband Matthew Koma, as well as Luca, 12, with Mike Comrie - told PEOPLE: "I feel like our big connection to one another, even though we're pop stars or on TV, is we love our kids.

"They were little baby worms when we all first got together and started music class at my house. Now, we're in art class together, and we're in gymnastics class together, and we're just, like, moms."

Hilary loves having the support of her showbiz pals.

The 'Lizzie McGuire' star shared: "Everybody's super hardworking.

"Sometimes we're all showing up with hair and make-up rushing from a job, and sometimes we look like literal trash, so it's just nice to be in the trenches with them."

What's more, Hilary believes her kids are benefiting from growing up alongside the children of her celebrity friends.

The actress explained: "I actually really wonder if, when the kids are older, they're all still going to be friends, and if it's going to be helpful having friends [whose] parents are somewhat in the public eye.

"With Luca sometimes that was weird, or could be still weird. I think he's navigating it pretty well, but it's just a strange thing. I wonder if Mae-Mae growing up with kids that have other parents like that is doing to be comforting in a way ... Time will tell."