iona costello , 51 , and her 14-year-old daughter , have been missing for almost three weeks after last being seen on march 30 near their home in the wealthy seaside village .
their car was found in a parking garage on 42nd street in manhattan , but the pair , who often went into the city for theater and art museums , left no other trace of their whereabouts .
iona costello 's husband george , the co-owner of costello marine in greenport , died from a heart attack in 2012 .