Hi Kay, and welcome to WikiTree. If you would upgrade to a family membership and add a tag for the Chittick name you would be connected to about 140 other Chitticks that are already here. I found 3 or 4 Williams, but they do not seem to be the one you are searching for. I searched for a Patrick, Michael, Frances and a Francoise Chittick, but didn't find one. I did, however, find 15 Chitticks that were from Ireland.
Good luck in searching for your ancestors, welcome again to WikiTree, and I hope you enjoy it as much as I do.