My 14 Year Old Granddaughter Was Prescribed Prozac 10 Mgs

My 14 year old granddaughter was prescribed Prozac 10 mgs for depression. One month later she sustained a moderate concussion in a car accident. She has all the classic symptoms of the injury , and seems to be recovering well except for the fatigue factor...she sleeps 20 hours nearly every day and is so zapped of energy. I have taken anti depressants for 30 years and so has my brother, for both of us we cannot tolerate taking the medication in the morning as it impaired our cognitive function and left us so extremely tired...moved them to the early evening and wake up rested and energetic. I am concerned that the Prozac is exaserbating or prolonging the fatigue from the concussion I want to change to change to nighttime...what do you think ?