Petrochko, Katheleen (Ewsuk) of Somerville, March 26, 2017, at age 91, formerly of Elmira Heights, New York. Loving mother of Natalie Carr-Harris and Anne and Harold Oshima. Cherished grandmother of Gabriel and Arley Carr-Harris, Rebecca Carr-Harris, Rachel and Nic Aldrich, Andrew Carr-Harris, Michael Oshima, Daniel Oshima, David Oshima, and Kathleen Oshima. Beloved sister of Gloria Ewsuk and the late Sonia Palladino, Gabriel Ewsuk, and William Ewsuk. Visiting hours at the Rogers Funeral Home, 380 Cambridge St., Cambridge on Friday, March 31, 2017 from 4:00 to 8:00 pm. Funeral service at the Holy Trinity Church, 165 Park Drive, Boston on Saturday, April 1, 2017 at 9:30 am.