I did find a Mary Winifed Kenefick who died in Surrey England in 2005. I no longer have the international version of ancestry.com so cannot give any more info than that. I did see the border crossing into New york state by Niagara Falls from Canada. I also found quite a few other travel documents back and forth from New york to Ireland. It could be her but am unsure. There is also a SSDI for Mary Kenefick for Nov 21, 2002 in New York. It is possible to order the document but I know that it will cost some money. If she did not marry, this could be her. I have also found quite a few Mary Keneficks on Familysearch.org. This is a free website and you may be able to figure out something from there. She seems to have a very popular name. Do you know if she had any brothers or sisters sometimes you can find info through them.