I post this because Burke's Peerage gives no dates for her:
Ruth, Countess of Carrick, died 16 July 1990, and is buried in North Carolina. The gravestone calls her simply "Ruth McEnery Carrick".
Ruth McEnery Carrick
Birth
16 Dec 1916
Chicago, Cook County, Illinois, USA
Death
16 Jul 1990 (aged 73)
Moore County, North Carolina, USA
Burial
Mount Hope Cemetery
Southern Pines, Moore County, North Carolina, USA
https://www.findagrave.com/memorial/159924374/ruth-carrickHer husband, the 8th Earl, died in North Carolina, but is buried in Ireland:
Theobald Walter Somerset Henry Butler
Birth
23 May 1903
Ireland
Death
31 Jul 1957 (aged 54)
Pinehurst, Moore County, North Carolina, USA
Burial
Killeen Cemetery
Thomastown, County Kilkenny, Ireland
https://www.findagrave.com/memorial/133288563/theobald_walter_somerset_henry-butler