My Three Imaginary Daughters

Meet my three daughters.  First, meet Constance. She simply keeps me going. Unwavering, I can always count on her. My second daughter is Grace. I admire her very much. She possesses a great ease of adaptation to life's craziness. My third imaginary daughter is Joy. I always look for her. Sometimes she hides and I have to think about Grace to find Joy. The best moments of my life are when my three daughters are in the same room, talking and laughing together. I try to bring them to class when I teach so they can share with others the power of their personalities. What are your imaginary daughters' names?