Because of your daughter's young age, it is difficult to discern if her behavior is a
reactionAllergic reactions
Allergic reactions to medication
Dermatitis, reaction to tinea
Drug allergies
Febrile/cold agglutinins
Insect bite reaction - close-up
Intradermal allergy test reactions
Positive reaction to allergen
Transfusion reaction to the developments you mentioned. Whatever the case, continue to set a frim limit and be sure to go beyond simply talking. That is, discipline her for any infractions (a fifteen-minute time out, coupled with, for example, loss of TV for an afternoon/evening) and have her return any stolen item. In addition, have her issue an apolgy and do something noce for the person from whom she stole. This is a time in development when children learn that simply desiring something does not mean they can have an item. She'll likely be fine if you are persistent in your expectations, limit-setting and follow-through.