We are definately talking about the same Mary Kate. She had four sisters Agnus, Margaret, Brigit and Anne Jane. My grandfather (Andrew) moved to Scotland with his mother Mary Kate and father Edward Mc Padden in 1921. Some of my papas brothers and sisters were, Elizabeth (moved to Glasgow), Annie, Stephen, Partick, John James, Michael Edward (moved to Glasagow), Mary Ellen and Thomas (moved to Glasgow). My papa is the only living relative alive and is living in Ardrossan Scotland with my nana Patricia.
They have two children Andrew and Delia (my mother) who if I am correct would be your cousins.
One of Mary Kate's sisters Anne Jane, moved to America for a while but returned to Ireland and bought a small holding which she left to my grandfather as she was his God Mother. Two other sisters moved to Edinburgh and one other sister remained in Ireland. This is all very exciting, please write back as I think we are related in one way or another and it would be interesting to share our information. Are you living in Ireland?.