I believe Andrew Thomas Nelson who is also a member of this Cree FH Network, is also your relation. His great-great-grandfather was George Cree, brother of your William Cree who married Mary Gill. I think that makes Andrew your 4th cousin! The parents of George and William were William Cree (Cree ID 9456) and Jane Wills, who were married in Lisburn in 1839.
Welcome to the Cree Family History Network. I am not related to the Northern Ireland Cree line but I look after the "other" website where we record the genelaogy of all Cree lines. That is the Cree Surname or Cree One-Name Study website. See the link (One-Name Study) in the main menu above.
At least one of your relatives is a member of this Network site as you have discovered. That is Leonard Cree in Drogheda, Ireland, who I believe is your second cousin as you both have William and Mary (Gill) Cree as your great-grandparents.William has Cree ID number 9457 in our Cree Genealogy Database and this helps to distinguish him from all the other William Crees. (There are over 11,000 people in the database and quite a lot of them are named William Cree!). Leonard Cree is not shown as the database doesn't display details of living people. I met Leonard a few years ago when I was visiting Ireland (my wife Marian and I go there most years). Leonard's father, also Leonard Cree, is shown however. He has Cree ID 9463. You can enter a Cree ID into any of the green Quicksearch boxes on the Cree Surname website.
Harriet Cree's ID is #9479 and her 1926 marraige to William Watters (#11082) is shown there but we have no further details. Her ten elder brothers and sisters are also shown with some descendants. I have a note that I have been in touch with a James Allen who is, I believe, a son of Harriet's sister Lizzie as she married a Thomas Allen in 1931. I will be able to look up his email when I get home to England after next Monday (25th March).
I'll be happy to add further details of your family to the database if you will send me details of births marraiges and deaths with dates and places of each event. Other events can also be added and these often add interest to the story. The website automatically excludes living people for being shown but they can be recorded on my off-line database for future referecen and making contact.
This Network website is operated by Trevor Cree of Sussesx, England. He and I have collaborated on Cree research for many years.