The "Sin City" star - who has daughters Honor, seven, and Haven, three, with husband Cash Warren - said she was worried about the opinions of other mothers when she gave birth to her eldest child, reported E!Online.
"Doesn't it feel like the mean girl thing from high school sort of just transforms into adulthood through motherhood? I think it has to do with hormones, right?...
"And then your hormones go crazy again when you're pregnant and having a baby - and even when you're breastfeeding. And I feel like maybe it's just all those hormones, and people don't know where to put their energy, so they just start clashing," she said.