Final answer:
The nurse should administer Oxytocin in this situation to control heavy lochia and firm the boggy fundus.
Step-by-step explanation:
The nurse should expect to administer Oxytocin in this situation.
Oxytocin is a hormone that stimulates uterine contractions and helps with the expulsion of the placenta. It also aids in reducing postpartum bleeding and promoting uterine involution. Administering oxytocin will help to control the heavy lochia and assist in firming the boggy fundus.