How will Marc Anthony's three other children react to their new step-siblings?

Every milli-second of J.Lo's pregnancy has been documented, it seems. You couldn't turn on the TV or log onto your computer without seeing another shot of her in a new designer maternity dress. But one thing that hasn't been talked about much is Marc Anthony's three other kids: Arianna, 13; Anthony, 7; and Ryan, 4. What about them?

We talked to Ericka Lutz, author of The Complete Idiot's Guide to Stepparenting, about the struggles a family often faces when bringing new babies into a blended family, and how to overcome them.

Respect older kids'  feelings: "Kids' reactions to the infant are not always warm and welcoming," she warns. "The youngest child may mourn his lost position as 'family baby' as he moves to a 'middle child' position. If handled incorrectly, and if the parents are too wrapped up in their howling little bundles of joy to reassure the older children, a new baby (or in this case, babies) can block up the relationship between kid, bio-parent, and stepparent."

Let babies work their magic:  Have you got a kid or stepkid who's reluctant to warm up to the baby? Don't beg, cajole, or bribe, says Lutz. "Let the baby handle it," she advises. "Babies are brilliant at seduction. The first time a half-sibling encounters a toothless smile, he'll be wooed!"

Allow bonds to build over time: "Once the baby is born, kids generally relate to their new half-sibling the same way kids always relate to siblings: with a combination of love and hate, interest and disinterest, connection and repulsion. Half-siblings are brothers and sisters to each other. They'll build their own relationships, and they'll have their own pleasures and disappointments with each other. Parents don't have a lot of control over that."