Edith R.Blair;89;of 577 South East Anchor Lane;Port St.Lucie;Fla.;died Tuesday;Oct.3;1989; in Martin Memorial Hospital;Stuart;Fla.  She was born in Charleroi;April 29;1900;a daughter of the late William and Etta Stitt Roley.  Mrs.Blair was Protestant by faith and had spent most of her life in the Belle Vernon area before moving to Florida two years ago.  In addition to her parents;she was preceded in death by her husband;Dallas Blair Sr.;who died Nov.23;1966;a son;Dallas Blair Jr.;who died July 7;1983;and a sister;Mildred Charles.  She is survived by two sons;David P.Blair and Jack T.Blair;both of Port St.Lucie;Fla.;a sister-in-law;Jessie Rae Blair of Belle Vernon;six grandchildren;and five great-grandchildren.   Friends will be received at the Ferguson Funeral Home Inc.;700 Broad Ave.;Belle Vernon;Thursday;2 to 4 and 7 to 9 p.m.  Funeral services will be held from the funeral home Friday at 11 a.m.;with the Rev.James Gardner;of the People’s Bible Church f Belle Vernon;officiating.  Interment will be in the Belle Vernon Cemetery.  The Ferguson Funeral Home Inc.is in charge of arrangements.