I have a fairly large CRUD winform app that is set up to display forms embedded in tabcontrols. I want to have objects for Person,(has a) Enrollment,(has a) Plan that hold and
You will need to seperate your data, logic and GUI.
Look into the Model-View-Controller pattern.
If you think it's too complex in your case you might just create a central controller class to hold the central data. Pass on this object in every form constructor and you're done.