You can keep building your tree in Family Tree Builder,
each time you make a change, you can publish the updated tree to your Family Site.
Your Site Members will be able to see the tree grow, but they will not be able to edit it.
If you want to remove the tree from the Family Site, go to the Family Tree > Manage Trees page, and remove it. I recommend that you leave it there - when you publish your tree it is shared with your family, and you will also get Smart Matches with other published trees.