It's Honor Marie and Haven Garner Warren's cover girl debut!

The fashionable 3-year-old and 7-month-old girls joined their movie star mamma Jessica Alba on the cover of Parenting magazine's April issue, and little Honor got to wear a tiara for part of the shoot!

Alba revealed to the mag that she is definitely the "disciplinarian" of the family, confessing:

    "I think it's because I was kind of a naughty kid myself: I'd push my parents' buttons and test them to see how much I could get away with. Cash, meanwhile, was always the perfect kid -- the straight-A student who was everyone's sweetheart. It was never in him to be naughty."

The Fantastic Four star also revealed how she was able to get her only daughter excited about the idea of a sibling. "We'd say things like, 'You know, when the baby comes, babies can't have lollipops or go on a swing. They can't play dress-up,'" she said. "Honor realized she was going to be the cool sister. Now, she's really into being my helper. When I change Haven's diaper, I ask her, 'Can you throw this away for Mommy?' or 'Can you get me the wipes?' She's really into it."

Hubby Cash Warren has also become a "super dad," since the girls were born, says Alba. "If I'm with Haven, he'll make Honor's lunch or take her to the park. They see movies or draw together -- she'll even watch sports with him." Aww!