Rose H.Rousseau;Mt.Vernon;Ohio;died Sunday;Oct.5;1986;at 1 a.m.in Knox Community Hospital;Mt.Vernon.  She was 80.  Mrs. Rousseau was born in Juneau;Pa.;on Aug.8;1906;a daughter of the late William and Sarah Reed Wehry.  She moved to Mt.Vernon in 1949.  In addition to her parents;she was preceded in death by her husband;Harry;two brothers;Guy and Sim Wehry;and a sister;Mrs.Fink.   Survivors include a son;William of Ford City;a daughter;Ora Jean Rousseau of Mt.Vernon;a sister;Martha Gaskin of Westminster;Colo;five grandchildren and eight great-grandchildren.  Friends will be received at the Flowers-Snyder Funeral Home;619 E.High St.;Mt.Vernon;on Monday from 1 to 3 p.m.  Funeral services will be held at the funeral home Tuesday at 8 a.m.with committal services at 2:30 p.m.at Belle Vernon Cemetery with the Rev.Thomas St.Clair officiating.  Burial will be in Belle Vernon Cemetery.  The Flowers-Snyder Funeral home is handling the arrangements.