Leaking breasts do not necessarily indicate that they are full. Breast milk leakage can occur for various reasons, such as hormonal changes, let-down reflexes, or even pressure on the breasts. Some women may experience leakage even when their breasts are not overly full. On the other hand, some women may have full breasts without experiencing any leakage. It's important to note that the feeling of fullness or engorgement, rather than leakage, is a more reliable sign of breast fullness.