What are the general macroscopic differences of these two conditions?

Mandy is a 16-year-old competitive figure skater who practices several hours a day with her coach at the skating arena. Because of her
extremely active lifestyle and restricted diet to maintain her athletic physique, she experiences ongoing amenorrhea. One day during
practice, she landed a jump and fell to the ice in pain. Her left foot swelled up almost immediately, making it difficult for her coach to
remove the skate. At the hospital, radiographs revealed a fracture of the fifth metatarsal bone and general radiolucency of all the bones in her foot. A follow-up DXA revealed a bone mass of 2.7 standard deviations below mean.
Answer the following question on an advanced Pathophysiology level:
1. What is the etiology of Mandy’s premature osteoporosis, and how is her condition thought to contribute to a decrease in bone density? 2. Knowing what you do about bone mineralization, why does a deficiency of estrogen in women lead to osteoporotic change?
3. Osteoporosis and osteomalacia both involve abnormal bone mineralization. What are the general macroscopic differences of these two conditions?