I'll help ensure you'll be able to get a copy of the statement you've sent to your customer, @canadacrs.
You can simply pull up the Statement List report and check/locate the statement number from there.
Once completed, look for the statement number under the Num column, and the customer's name will be reflected under the Customer column.
I've added this screenshot for additional reference.
You can also check this article for further details about customer statements: Create customer statements.
Leave a comment below if you have any other questions about statements. I'm just a few clicks away to help.