Frank Dicopoulos' daughter Olivia has been playing Maureen for a couple of years. I don't think that the baby playing Frank and Natalia's daughter was Jessica's real life daughter. JL's daughter was only about 3 months old at the time that scene was filmed and Francesca looked older than that to me. I'm not positive it wasn't her but I really don't think so.
I know for sure that the children that played Christine and Remy's baby, the older Henry, and the older Colin were played by actors, not cast members' family.