Bell, 32, is a cast member of Showtime's "House of Lies." She is engaged to "Parenthood" actor Dax Shepard, 37. They have been dating since 2007.
"They're so excited -- they're both ecstatic. They can't wait to become parents," a friend told People.com. "Kristen had a little bit of morning sickness early on, but she just started shooting the second season of 'House of Lies' and is feeling great now."