C# Entity Framework - Stack Overflow when inserting data into child table

I am brand new to C# and Entity Framework. I have been used these tutorials and StackOverflow to give me a better understanding.

1. http://developer.telerik.com/featured/working-with-databases-through-visual-studio/
2. https://msdn.microsoft.com/en-us/data/jj193542

Using the Code-First approach, I have created a parent table and inserted data into the table no problem. When I had the parent table working correctly, I added the child table. I am now trying to insert data into that child table. However, I always get a stack overflow error. I think that there is something wrong with my mapping, but I am not sure what.

The following is my code. This is where I define the database context and the objects for the database.

public class DatabseContext : System.Data.Entity.DbContext
{
    public DbSet<Parent> Parents { get; set; }
    public DbSet<Child> Children { get; set; }
}

public class Parent
{
    private Guid parentIdVal;

    public Parent()
    {
        Children = new List<child>(); 
    }

    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid parentId
    {
        get { return parentIdVal; }
        set { parentIdVal = Guid.NewGuid(); }
    }

    [Required]
    [StringLength(4)]
    public string parentData { get; set; }

    public virtual List<Child> Children { get; set; }
}

public class Child
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid childId
    {
        get { return childId; }
        set { childId = Guid.NewGuid(); }
    }

    [ForeignKey("Parent")]
    public Guid parentId { get; set; }

    [Required]
    [StringLength(65)]
    public string childData { get; set; }

    public virtual Parent Parent { get; set; }
}

I have a different class what parses a file and inserts rows into each table. This is the code:

    private static void addParentRecord(String source)
    {
        using (var db = new DatabaseContext())
        {
            Parent parent = new Parent(); 
            addDataToParent(parent); 

            createChildren(source, parent);
            db.Parents.Add(parent);
            db.SaveChanges();
        }
    }

    private static void createChildren(String source, Parent parent)
    {
        Regex regex = new Regex(pattern);
        foreach (Match match in regex.Matches(source))
        {
            Child child = new child();
            child.childData = match.Groups[group].Value; 
            parent.Children.Add(child); 
        }
    }

So the code creates both the parent and the child tables. It creates both the parent and the child objects and populates the objects. When I go to save the database changes, however, it continually calls the get ChildId and I get a stack overflow. There is some loop somewhere. I think it is because I don't have the parent-child mapping set up correctly.

Any help, pointers or links would be greatly appreciated. Thank you.