I think this may be your girl:
Mary Caroline OATES b 1853 married Lawrence W. SEGAR b 5 May 1852 Wyalusing, Bradford PA, d 18 Oct 1903 New Orleans, Jefferson LA. He was son of Collins Marshall SEGAR (1812-1896) + Charlotte SPALDING SPAULDING (1814-1901). She was dau of James OATES + Addie SEGAR (abt 1835-). I don't have data for James OATES, but Addie SEGAR was dau of Joseph Meserve SEGAR (1803-1896) + Mary __ (1809-). Joseph was son of Josiah SEGAR (1747-1830) + Jeanne "Jane" Meserve (1763-1830). Josiah moved fr Newton, Middlesex MA to Unity, Waldo ME. Sometimes Maine is referred to as Canada at that time. Jeanne Meserve is a French name. She was b Brewer, Penobscot ME. Her father John was b 1728 ME and died in 1790, Bridgton MA. Let me know if this is helpful...