While orange peels contain citrus oil and d-limonene which can
cause vomiting there are no other toxic concerns. So sounds like Charlotte is handling this small amount of peels fine at this time.
Source of this information was from a similar post on a veterinary website that was answered by Tina Wismer, DVM, DABVT, DABT from ASPCA Animal Poison Control Center An Allied Agency of the University of Illinois.
As far as other fruits and vegetables, remember that raisins, grapes, onions, garlic and shallots are toxic to dogs and cats.
Hope that helps.