By peoplestaff225
Updated June 11, 2008 10:15 AM

Being a big sister to two little brothers is a reality that 4 ½-year-old Ella Rae is still coming to grips with, her dad Mark Wahlberg recently told US. While at first his daughter was "extremely disappointed" to learn that the baby Mark expects in September with fiancée Rhea Durham was a boy, Mark said Ella is beginning to understand the perks of being the only girl. Said Mark,

The reality of a third child is something Mark and Rhea, who are also parents to 2-year-old Michael, are also coming to grips with in their own way; Mark revealed that he’s losing his home office in order to make room for the baby’s nursery. If he’s feeling intimidated by the notion of being a dad-of-three, however, he’s not showing it. Mark told People the couple is "thrilled" to add to their family, adding,

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Mark’s co-star in The Happening actress Zooey Deschanel raved about his enthusiasm for fatherhood, telling US that the 37-year-old actor "loves his children so much" and "talks about them all the time." Mark said making the movie — which opens on Friday — was a priority because it’s family-friendly, something that has become increasingly important to him.

Sources: US, People; Photo by Stephen Lovekin/Getty