Thanks for writing your query to us.
Since the last Xray showed no lesion so the doctor might have stopped her medicine.
Now whenever your wife gets temperature kindly document it. Take temperature with a thermometer & write it down .This will help in looking at the pattern of rise in temperature. If your wife is on some medicine than that can also give rise to fever thats called drug fever that means fever due to any drug. If there is high fever
than kindly show your wife along with the temperature chart.