Final answer:
A client with a boggy, displaced fundus above the umbilicus after a vaginal delivery should be assessed for uterine atony.
Step-by-step explanation:
After a vaginal delivery, a client's fundus is 3cm above the umbilicus, boggy, and located to the right of midline. This finding suggests uterine atony, which is the lack of uterine muscle tone. It is important to assess for uterine atony as it can lead to postpartum hemorrhage. The client may require interventions such as massage of the uterus, administration of uterine contracting medications, and monitoring of vital signs and bleeding.