Final answer:
The most appropriate nursing intervention at this time would be to closely monitor Marie's vital signs and assess her condition regularly.
Step-by-step explanation:
The most appropriate nursing intervention at this time would be to closely monitor Marie's vital signs and assess her condition regularly. This can help the nurse identify any changes that may occur and take immediate action if necessary. Additionally, the nurse should ensure that Marie is comfortable and provide any necessary medications or treatments as prescribed by the healthcare team.