Mamie Gummer and Ben Walker
07/20/2011 at 10:00 AM EDT
Meryl Streep's latest role? Mother of the bride.
The actress's eldest daughter, Mamie Gummer, tied the knot over the weekend, PEOPLE has confirmed.
Gummer, 27, who starred in ABC's Off the Map
, wed actor Ben Walker, 29, Saturday at the family estate in Connecticut.
Among the 150 guests helping the couple celebrate their nuptials at the lakeside ceremony: Claire Danes
, Tracey Ullman and Laura Linney, reports The Washington Post
Gummer, who met Walker while performing in Broadway's Dangerous Liaisons
in April 2008, paid tribute to tradition in her grandmother's gown.
The newlyweds announced their engagement
in October 2009.
"He was the Keanu to my Uma," she told PEOPLE at the time. "We were kind of pals first. And he's very patient."