Biography: ​From Wikipedia, the free encyclopedia.   Megan Henning (born September 13, 1978 in Baltimore, Maryland) is an American actress. She is known for playing Meredith Davies on 7th Heaven and Monica Shaw on David E. Kelley's The Brotherhood of Poland, New Hampshire. In 2008 she began playing the recurring role of Judy Hofstadt, Betty Draper's compassionate sister-in-law, on Mad Men. Description above from the Wikipedia article Megan Henning, licensed under CC-BY-SA, full list of contributors on Wikipedia.