Do you know if Bridget had a twin brother Patrick? The reason i ask is I located baptismal records on February 14 1859 for twins Pat and Biddy McGrath. Parents were Patrick McGrath and Mary Reidy. The parish was Kilmacduane/Cooraclare. Here is a link to the register page with the baptisms.
I located the record on the subscription site FindMyPast.ie There was one other Bridget McGrath baptism in Co. Clare in 1859 but it was in November.
Let me know if you think this record pertains to your ancestor and I will look for other siblings.