Abby Rourke from Derrinkip

I am searching for Abby Rourke/ORourke born ca 1844 in Derrinkip, County Leitrim.  A birth cerificate was never found for her in Ireland, but we know she came to Rhode Island.  We have evidence that she is the sister of the brothers we have additionally found in Rhode Island.

My question is:  Is Abby a derivative of some other name?  I can find NO Abbys anywhere in Ireland, or in the States, for that matter.  Might there be another name for her?.  She goes by Abby from her marriage in 1863 to her death in 1917. But I find no Abbys before that on either side of the ocean..

Thank you for any help you can give me.

Barbara

:-)