Martha MacIsaac will star in a comedy called 1600 Penn, based on the lives of a U.S. president's family.
MacIsaac, 27, got her start in television at the age of 12 playing the title role of Emily of New Moon.
In this new venture, she is playing the president's straight-laced eldest daughter, Becca Gilchrist, who tussles with her stepmother.
"So, we are the first family and we live in the White House. And it's sort of Modern Family meets West Wing, but a little less political," said MacIsaac.
"It's more just what if an ordinary, normal family that has its problems and its funny people, and everybody's kind of high emotions and what that's like under the microscope of being in the most powerful address in the world."
The sitcom also stars Jenna Elfman from Dharma and Greg and Bill Pullman from Independence Day.
After spending four years trying to break into television in Los Angeles, MacIsaac said she was ready to leave when this part came along.
"This one I just fell in love with instantly and knew I was right for it right away when I read it. I was so excited," said MacIsaac.
"And it came and went. I was really close to getting it, and then they went in another direction and it was cast with someone else. And then at the last minute they brought me back in and now we're here and I'm so excited."
1600 Penn debuts in January.Suggest a correction