Helen Yeaton;87;of Belle Vernon;died Thursday;June 24;1999;at 3 p.m.in Mon Valley Hospital;Carroll Township.  Born March 31;1912;in Washington Township;she was a daughter of the late John and Sophie Owatt Kuklar.  A lifelong resident of the Belle Vernon area;she was Catholic by faith.  Survivors include her husband;Frederick R.Yeaton;two sons and daughters-in-law;Fred H.and Lynne Yeaton of Ocale;Fla.;and Gordon and Janice Yeaton of Belle Vernon;two sisters;Margaret Morgavo of Turtle Creek and Violet Wargo of Beaver Meadows;three grandchildren;Chris Yeaton;Candice Letter and Vicki Kutska;and three great-grandchildren;Jonathan and Jake Yeaton and Vicki Kutska.  In addition to her parents;she was preceded in death by a granddaughter;Tammy Yeaton;three sisters;Ann Kramer Moser;Sue Kuklar and Katherine Stec;and four brothers;Andrew;Victor;Joseph and Alex Kuklar.   Friends will be received Sunday from 2 to 4 and 7 to 9 p.m.in the Ferguson Funeral Home Inc.;700 Broad Ave.;Belle Vernon;where a Prayer service will be held Monday at 10 a.m.with the Rev.John Cindric;pastor of St.Sebastian Roman Catholic Church;Belle Vernon;officiating.  Entombment will be in Belle Vernon Cemetery.  The Ferguson Funeral Home Inc.is in charge of arrangements.