Looking for Ellen McCormick/McCormack

I am looking for my great-great-grandmother Ellen McCormick born about 1834.  For Ellen, oral history says Co Limerick, US censuses say only "Ireland," her obituary doesn't give a birth place, and her death card says only "Ireland."  Her cemetery record says Co Galway.  She and her husband were Roman Catholic.

In the 1850 US Census there is a listing for *an* Ellen McCormack as 16 putting her birth about 1834 in Ireland which fits with the other information we have.  The census is the last before she married Luke Casey in 1852.  It lists all as born in Ireland meaning that they would have arrived between 1848 and 1850 (or that the census information isn't completely right), none as married in the past year and none in school.  It shows the family as of the 28th of September, 1850, in Ward 11, Cincinnati:

John McCormack 38 M Laborer

Mary A 30 F

Ellen 16 F

John 12 M

Mary 9 F

Thomas 7 M

Margaret 4 F

Joanna 2 F

(Notice the repeating naming pattern of John, Mary Agnes, Thomas from this family and Ellen’s children.)

Any help finding Ellen or Luke would me most appreciated.  Thanks!