Robert F. Kennedy's granddaughter and her son presumed dead after canoeing accident in Maryland

The grandson and adult daughter of former Maryland Lt. Gov. Kathleen Kennedy Townsend are presumed dead after the pair's canoe apparently capsized in the Chesapeake Bay, Townsend said Friday.

In a statement issued Friday night, Townsend said the search for her daughter, 40-year-old Maeve Kennedy Townsend McKean, and 8-year-old grandson, Gideon, was now a recovery effort.

“With profound sadness, I share the news that the search for my beloved daughter Maeve and grandson Gideon has turned from rescue to recovery," Townsend said in the statement."Maeve was vivid. You always knew when she was in a room," Townsend added. "Her laughter was loud, unabashed and infectious. She did everything with her full self and her whole heart."

The pair went missing late Thursday afternoon in waters near the pair's Shady Side, Maryland home, about 25 miles south of Annapolis, officials said.

Gov. Larry Hogan said that he had been in touch with Townsend "and on behalf of the people of Maryland I expressed our most heartfelt sympathies and prayers to her and to her entire family during this difficult time."

A Maryland Department of Natural Resources statement said a preliminary investigation "revealed that the pair may have been paddling the canoe from a residence in Shady Side, MD out into the bay to retrieve a ball and were unable to paddle back to shore."

An overturned canoe, approximately matching the description the pair were in, was later found, the department said.

Kennedy Townsend comes from one of the most famous political clans in U.S. history. She’s the oldest daughter of Robert F. Kennedy and niece of former President John F. Kennedy and Edward M. Kennedy.

She served two terms of lieutenant governor of Maryland.

Maeve Kennedy Townsend McKean is executive director of Georgetown University's Global Health Initiative.

McKean got into a very public spat last year with her uncle Robert F. Kennedy Jr. over his son's skepticism of vaccines. She, her mother and former U.S. Rep. Joseph P. Kennedy II penned a tough editorial taking Robert F. Kennedy Jr. to task.

"He helped to spread dangerous misinformation and is complicit in sowing distrust of the science behind vaccines," they wrote. "We love Bobby. However, on vaccines he is wrong."