A. First, have you asked her calmly how she got the items? If she says a friend or the teacher gave them to her, check with the friend's parent or the teacher to be sure.
If it turns out she has taken items she shouldn't have, talk with her about why it's wrong to take things that don't belong to her. How would she feel if somebody took something she values?
It's important that you have her return the items and apologize to the owner or owners -- with parental supervision, of course. It will be difficult for her, but you can talk with her about what she should say, and why. Practice with her beforehand. Remember: Be constructive.
She may be envying what others have. Talk with her about how you yourself get items you want. Perhaps you ask to borrow something from a friend. Your little girl must understand that friendship is very important -- and it takes honesty. People must never take things from friends. But they can ask to borrow, and often friends will say yes. If they say no, that's their right.
No doubt sometimes you save your money to buy something you want. Talk with your daughter about that, too. You might work with her on ways she can save money to buy something she wants: special chores that can earn "pay," a way to save cash gifts from birthdays, and so forth.
Help her understand that everyone can't have everything. That's not an easy lesson -- but it's an important one.