If Francis and Margaret were married in a Catholic ceremony c1858 there will be no civil marriage certificate (registration of Catholic marriages began 1864) so you would need to search for church records (if they exist) but to do so you need to know where they lived.
IGI shows one of their children:
George Frank Moore born 1 Jan.1872 Co. Kilkenney.
Think this might tie in with your other query?
This now gives you a possible area to search for more information.