Like Francis I think your Kathleen was probably shown as Catherine to simplify recording it in census records etc.
In the IOM 1891 census there is a Catherine Agnes Corrin 3 years of age at Marown. (the only one, one other at 5yrs) Her family is Thomas Corrin 33 yrs, Mary 28yrs and children Thomas E 8, William A 6, John R 5, Catherine A 3, Francis A 2 and Mary A 7 mo's. They are also in the IOM census in 1901 at Marown except Thos and Wm the children are no longer there.
Should you wish to follow this lead further there is a marriage of Thomas Corrin and Mary McCormick Aug 10, 1882 in Onchan. Thomas Corrin may also be the son of Thomas Corrin and Mary Shinin of Santon IOM. All these locations are in close proximity ie Santon borders Marown so they could be related.
Also you can get more info off Fam search.org. If you call for the children of Thomas and Mary it gives you christening dates etc.