McLuen/McGlenn and Carney/Kearney in Counties Cork and/or Roscommon

My great grandmother Elizabeth Carney (Murphy) Sharon, immigrated to US as a young child with her mother Elizabeth McGLENN.  Elizabeth the younger always said she had been born in County Cork. Elizabeth McGlenn's death certificate, supplied by her daughter, showed her father's name as John McGlenn (and variants of this surname are on other documents also--no original birth documents).  Elizabeth McGlenn then married James Murphy, had two more daughters, and settled in Detroit, Michigan, USA.  Elizabeth the younger took her stepfather's name when she married, but always complained of not being treated as a full daughter by Murphy.  Her married name (Sharon) is not Irish but Swiss (probably an anglicization of Scharen).

Since CARNEY thus appears not to be the older Elizabeth's maiden name, it is likely--but not proven--to be her father's name.  So, tentatively:

Unknown Carney------

                                    Elizabeth Carney (1869-1943, Imm ca 1872)-----Annetta Sharon---Shirley Dean---6 Hamming sisters

Elizabeth McGlenn (1849-1923, Imm. ca 1872, daughter of John McGlenn)

DNA--My sister with the most Irish DNA  (only 8% even in her) localizes on Ancestry DNA to County Roscommon.

Additionally, she (and my other 4 sisters and I) all have multiple matches (at the 3rd and mostly 4th cousin level) on our Ancestry Match Lists to members of a McLUEN family in Iowa, USA whose Irish origin story starts in Strokestown (and Scotland before that).

Richard McLuen (1820-1865) married Susan Robertson (1820-1855).  After Susan died and Richard was ill, oldest son William--already in U.S.--brought several of his siblings (Delia, John, Sarah, and Susan) to the U.S. before 1870. Their descendants are our DNA matches. 

I am wondering if McGlenn & McLuen are versions of the same name and possibly that Elizabeth McGlenn is a sibling, half-sibling or first cousin to William McLuen et al.