Mood changes post delivery are very common and occurs in upto 40% of women. Most are self limiting.
But if it is not improving then she might be developing post partum depression.
It should be identified and treated at the earliest.
Untreated post partum depression can be very devastating for the mother and the newborn.
Next Steps
contact a psychiatrist at the earliest
Health Tips
allow her to ventilate her feelings, not leave her alone, motivate her to seek help