The Australian Whale Rider star, 19, hit the headlines when she revealed she was pregnant at the age of 17.
She confesses her partner of four years, Bradley Hull, proposed to her just months before she gave birth to their daughter Felicity-Amore in April 2007, and the couple has "been engaged for two-and-a-half years".
However, Academy Award nominee Castle-Hughes insists she is in no rush to exchange vows.
She tells People.com, "It's a very long engagement but no immediate plans. Eventually it will happen. I love him and we will be together for the rest of our lives."