I’m not too surprised by you getting DNA matched for Neely in Co Derry as it is a surname found in the northern counties of Ireland.
Did you check the entries in the original Holycross parish register? If not, you should. They are free at http://registers.nli.ie
Check for the home townland of the family in the marriage record and the subsequent baptisms. When Margaret married Michael Fogarty, what was her home address?
Hope this helps