Can a pregnant woman's mood affect her fetus' development?

Fetal development: Fetal development is mainly under genetic control. Providing good nutrition for the developing fetus is also important. Not much evidence that mood has much to do with development, though.

Metaphysical questio: Your question is metaphysical and i cannot answer to those ramifications. I will say, though, that maternal sorrow, anxiety, depression, stress do affect the pregnancy adversely and increase the risk for small babies, preterm birth and cesarean section. A healthy, optimistic mood is essential in all aspects of life, including reproduction!