Best practice for Handling NHibernate parent-child collections

So in a typical model where you have a parent that can have many children and a child that can have only one parent, how do you manage the adding of children. I have been using this approach;

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

    public IList<Child> Children
    {
        get;
        private set;
    }
}

public class Child
{
    public Parent Parent
    {
        get;
        set;
    }
}

var child = new Child();
var parent = new Parent();
parent.Children.Add(child);
child.Parent = parent;

Problem is that everywhere i want to add a new child i've got to remember to add a reference to both the child and parent and its a bit of a pain. I could just add an AddChild method to the parent class and make that responsible for adding children - the problem now is that there is 2 ways to add a child, through the Children property and the method. So is this a better solution?

public class Parent
{
    public Parent()
    {
        children = new List<Child>();
    }

    private IList<Child> children
    {
        get;
        private set;
    }

    public IEnumerable<Child> Children
    {
        get
        {
            return children;
        }
    }

    public void AddChild(Child child)
    {
        children.Add(child);
        child.Parent = this;
    }
}

Are there any guidences for best practices on this, and what do you do?