Katie Cody was a cousin to Bridie Warren (nee Cody). After Bridie died in 1967, Katie married her husband Jim Warren in 1969 in Dun Laoghaire. Catherine (Katie) Warren die on 6 August 1981 in Dun Laoghaire. Mystery solved - Katie didn't marry her sister's husband, but her cousin's husband. Thanks for all your help!