Having a 5-year-old and a 2-year-old under the same roof is a delicate balancing act — and one that proud mother Jessica Alba is just starting to truly appreciate.

“Their needs are a little different now,” the actress told PEOPLE of daughters Honor Marie and Haven Garner while attending the second annual Baby2Baby Gala. “They’re getting to an age where they play together and they do fight, which is funny.”

Funny in the sense that the sisters don’t engage in straight fisticuffs, rather they involve themselves in the age-old ritual of sibling rivalry merging with sibling revelry.

“They steal stuff from each other!” Alba shares. “They’re constantly snatching things out of the other one’s hand, destroying something that the other one’s building.”

For Alba, 32, who grew up with a sibling of her own, larceny and wanton demolition of property are par for the course. “It’s normal kid stuff,” she says with a laugh. “I did the same thing with my brother.”

What is still new for the Sin City star — despite having embraced her role as doting matriarch — is figuring out how to mete out appropriate discipline when met with, well, two adorable faces.

“So now it’s, ‘Stand in the corner and put your nose against the wall!’” Alba says. “My 2-year-old can last 15 seconds before she’s like, ‘Okay, I’m done!’, and then I’m like, ‘Wait, it’s not up to you!’ My 5-year-old can go for some time, like a minute or two.”

Though being the disciplinarian may not be her strong suit, Alba is certain of the one noble truth of being a parent.

“Every day I just want them to be happy and good and thoughtful,” she explains. “I just want them to be nice people.” – People.com