Preschool children have a wonderful imagination. In their minds, magic really happens as they don't have a lot of experience of how world works.
Make bedtime, or waking up in the morning, or both, regular times for reading together. Let your child tell you when she's had enough.
Playing has a serious purpose: it's how a child develops his or her character. This process depends more on what children perceive in their parents than on what the parents try to teach them in words. Basic ideals and attitudes towards work, towards people, towards themselves all get their start this way.