Authorities are searching for Fiona Grace Carroll, also known as "Kitty," who may have fallen into the water at the Kemah marina (KTRK Photo)Authorities are searching for Fiona Grace Carroll, also known as "Kitty," who may have fallen into the water at the Kemah marina (KTRK Photo)Search boats join the effort to find Fiona Grace Carroll at the Kemah Boardwalk (KTRK Photo)Search boats join the effort to find Fiona Grace Carroll at the Kemah Boardwalk (KTRK Photo)Authorities are searching for Fiona Grace Carroll, also known as "Kitty," who may have fallen into the water at the Kemah marina (KTRK Photo)KEMAH, TX (KTRK) -- Fiona Grace Carroll, also known as "Kitty," drowned after falling into the water at a Kemah marina