Is there any other information available for William? I have a 2x great grandmother with the maiden name of Carroll. All the information I have on her shows her living 15 - 20 miles south of Croom. I know she isn't a child of William but maybe he has a brother with a daughter named Margaret.
Margaret was born in 1845. I've found a baptism record that I believe is her. The information is parish Rockhill, Rockhill and Bruree in the Diocese of Limerick. Her father is Joanne (John)Carroll and Mother is Margarita Keane.
If this sounds familiar I'd love to hear.