Food issues and attachment??

My 3.5 y/o DD has FAS and RAD. She was also diagnosed with PICA. Not only does she eat all food she can get her hands on, she eats lots of non-food things too. We have had her for over 2.5 years! Never would I have imagined her eating issues being related to attachment. None of her docs know what to say except limit her eating because she has gained too much weight. She was taken into foster care at 6 weeks old and was in that foster home from 6 weeks until 9 months when we got her. I'd love to hear any other advice on this issue.