Faris and Pratt, 32, exchanged wedding vows in the summer of 2009 in a small ceremony in Bali. Faris had earlier said she wanted to have a big family, reported Aceshowbiz.
"She's very excited about the baby boy. She's six months along and everything is going great, just as planned. They're both happy and are really looking forward to being parents," a source said.
Before tying the knot with Pratt, the actress was married to Ben Indra whom she officially divorced in 2008.
