It is kind of normal for women to be moody after delivery. Most of them develop a mild type of postpartum depression (a phenomenon known as baby blues), starting a few days after giving birth, and extended by about 2 weeks.
Throughout this period, affected women may experience mixed symptoms, including increased sensitivity, anxiety, irritability, and sleeping issues. Baby blues will disappear eventually as the woman recovers from delivery and adapts to the new situation.
When this period extends beyond two weeks, it may indicate moderate or even severe postpartum depression. This type of mood disorder occurs in 2 out of every 10 women, and can last up to one year.