According to Jim: Season 8, Episode 5 - ProjectFreeTV

8 - 5: Two for the Money

When Cheryl learns of Jim's plan to use their twins in a movie starring Steve Guttenberg to get some money for Christmas gifts, she refuses to let him do it, but Andy and Jim decide to go through with the plan anyway, only to have it backfire when the producers cut the kids hair to make them look alike.