We have a customer requesting a source of receipt. We gave her a copy front and back of the check in question but she still wishes to have the source of receipt are we allowed to give this to her?

Can you elaborate further on the phrase "source of receipt"?

Source of receipt is something we request from FED by request from another bank for proof that an item was presented and paid. Usually we just get the cash/return letter that contains the item, but also contains many other items not related to the customer.