I am trying to find information on Marcus Shee who was passed away in 1643. Marcus was married to Ellen Grace (1565-1643), daughter of Oliver Grace. He could possibly be related to Sir Richard Shee (c 1550-1608) of Kilkenny.
Heather:
You likely have already reviewed these two Wikipedia articles but I pass them on FYI. Richard Shee did have a son Marcus and Marcus was the Mayor of Kilkenny town in 1631. You may also want to contact the Kilkenny library to see if they have any information.
Roger McDonnell
https://en.wikipedia.org/wiki/Richard_Shee