9 y-o f complains foot pain at night for months becoming severe and radiating to lower legs only at bedtime though.. whats going on?

It would be easier: To figure out in person. That not the case, i would look to see if she is flatfooted and if so get her arch supports. Knowing the site where the pain begins is important. It is possible her bone has not fully solidified yet, some docs refer to this as growing pains, when the secondary growth center is still closing. She could be in pain and compensating when walking making other body parts hurt.

Foot child: This is most probably apophysitis. This is an inflammation of growth plates, at end of joints.They can get swollen and painful in active children going through growth spurts.Take child to an orthopedic surgeon or podiatrist for an x-ray.Very normal but must be checked out to make sure there is no damage to the growth plate.