My mom has onfh (osteonecrosis of the femeral head) on both hip joints and she is 67 years old, is there some effective treatment to heal/resolve it?

Total hip replacemen: Once the bones have necrosed there are really only two option: 1- treat the pain for rest of your life. 2- total hip replacement should be considered.

No medical Rx : Unfortunately your mother has osteonecrosis , most of the time this is ischemic in nature most by degeneration atherosclerosis and osteoporosis and other traumatic in origin developing the vascular insuficiency and the posterior osteonecrosis the ideal is to see an orthopedic specialist and evaluate x possible hip replacement.

Depends why she has: It depends why she has it. There are a list of causes that she can discuss with her physician. She may need surgery of he hip.