The length of time for healing varies by the location of the stress fracture. Generally, the farther up on your leg the longer it takes. I had a stress fracture in the femoral neck (less trochanter). From what I read, about 16 weeks of no running and also avoiding other impact sports and even long distance walking.
I didn't know it was a hip stress fracture at first, thinking maybe it was just something with the iliopsoas. I took 10 weeks off, then got an MRI. Fool that I am, I tried to interpret my own MRI while waiting for the followup orthopedist appointment. So I thought the bone looked OK and I started powerwalking with a few 400 meter easy run intervals mixed in. I did 2 or 3 miles walking with about 3 to 5 quarter mile runs mixed in. I felt great doing this every other day for a week, then after 10 days suddenly my stress fracture pain came back in my hip, even worse than before. This was 11 weeks out. It hurt to walk, lie down, sit, for almost 10 days. After that I could walk pain-free for short distances, so I didn't use crutches.
So the timeline for bone healing was reset to square 1. The second time I followed the orthopedist's instructions. First month was only swimming, not even biking or elliptical. Then after a month I got into biking about 70 to 80 miles per week. My doc didn't let me powerwalk or run for 4 months.
After 4 months of healing, I started back gradually, first 15 miles per week walking for a couple weeks, then in weeks 3 and 4, I mixed in 400 meter runs (3 to 5), then after a month, 3/4 mile to 1 mile runs (2 to 4). By 2 months I was running continuously.