Megan Henning's most prominent recurring role on television was as Meredith Davies on moralistic family drama "7th Heaven"; the character of Meredith was the ex-girlfriend of a friend of one of the main characters, the teen son of the minister patriarch on the show. The plot line involving Meredith wasn't particularly focused on her character, but served more in decrying the non-marital sex involving teens on the show. Before "7th Heaven", Henning was part of the cast of the short-lived, quirky David E. Kelley drama "The Brotherhood of Poland, New Hampshire", which was similar in style and tone to "Northern Exposure" and "Picket Fences". Henning's character, Monica, was the daughter of the mayor on the show, played by John Carroll Lynch, and his wife, played by Elizabeth McGovern. In 2007, Henning had a relatively minor part in the notoriously campy thriller starring Lindsay Lohan, "I Know Who Killed Me", about a set of stigmatic twins (both played by Lohan) with a psychic connection who try and stop a serial killer. The following year, Henning had a recurring role on the 1960s period drama "Mad Men" as a sympathetic sister-in-law, Judy, of one of the main characters, Betty Draper, played by January Jones. Judy makes three appearances that all involve the care and later death of Betty and Judy's husband's father--Judy acting as a buffer and peacekeeper between the feuding siblings.