Kaligirl,
I’ve drawn a blank on a Corrigan connection that your grandmother mentioned unfortunately.
That said, I do find it interesting that she mentioned a Corrigan. I don’t know if she was ever in Ireland. If she wasn’t, for some reason the name struck a chord with her. Certainly your grandfather knew Corrigans, he was probably in school with some of them, one of his aunts married a Corrigan and one of his sisters married a man whose mother was a Corrigan. Those Corrigans were brother and sister. It’s intriguing.
In one of your posts you say the following: “I started searching for a Mary Corrigan and found a Mary Catherine Corrogan baptized in Westmeath in 1780 (a year before Christopher's birth).” Could I ask where you found that Chrisopher.
If Christopher's (died 1890) baptism record could be found it would be a major advance. There is nothing to confirm that he was born in 1816 at the moment.