Well first of all do you now have the item back?

If not, when you see her you could calmly ask for the item back. Ignore the insults. Don't tell her that you are upset or criticize her, just calmly ask for the item back. "Can you get it to me today?" This gives her the opportunity to return the item without "losing face", without feeling humiliated that she acceded to outright demands from you. Simply make the request calmly. Keep making the request calmly until she returns the item.

(And make certain not to lend her stuff again for a long time!).

What sort of reactions are you getting from your kids?