O’BRIEN, Kelleigh A., of Cambridge formally of Tewksbury, passed away suddenly on September 1, 2023, at the age of 37. Adored mother of Eloise and Madeline Donnelly. Beloved Daughter of Carol (Clarke) Peralta and James O’Brien. Loving sister of Katie Fredriksen, Karlie O’Brien, and Nevina O’Brien. Cherished granddaughter of Gilda Clarke (Pacheco) of Somerville and the late Carl Clarke, and Joan O’Brien of Watertown and the late Eugene T. O’Brien. Beloved aunt to Cecelia Grace Fredriksen. She is also survived by many loving Aunts, Uncles, Cousins, and dear friends. Visiting Hours will be held on Wednesday, September 6th from 4-7PM in St. John's Church, 2254 Mass Ave., in NORTH CAMBRIDGE. Her Funeral Mass will be held at St. John's on Thursday, September 7th at 11AM. Burial will follow in Cambridge Cemetery. For directions or to leave a message of condolence please visit www.keefefuenrsalhome.com