possible osteopenia in one monozygotic twin

A friend of mine has identical twin babies. There was some concern during the pregnancy because an ultrasound showed that one twin was larger; getting more nutrition and had more intrauterine “room to move.” They were delivered a little prematurely via C-Section, but seemed to be healthy and did well. Although one baby was bigger, the other seemed to be catching up.

At age 3 months, the smaller baby sneezed hard and then began crying inconsolably. The dad was concerned, so took the baby to the ER, where they did an X-Ray and found broken ribs.

The babies were both removed from the parents with accusations of child abuse.
Of course suspicions of child abuse should be vigorously pursued. In this case, I believe that abuse did not occur. The parents are going crazy and their babies are in a foster home. The father is facing criminal investigation.

With some online investigation, I’ve found several articles about discordance in bone density in identical twins and wonder if the rib fractures could have occurred because of this. Maybe more calcium went to one fetus than the other?

I would like to know if anyone knows of resources that might be useful here.