Yes, Felicity. You can add the sales tax information on the statement by turning on the List each transaction including all detail lines option from the Account and settings page.
Here's how:
Go to the Gear icon, then Account and settings.
Navigate to the Sales tab.
Scroll down and select the Statements field.
Click the List each transaction including all detail lines option.
Hit Save, then Done.
Once enabled, your client will receive a breakdown of the invoice item's amount and the sales tax included in the entry.
For reference, this is how the statement looks after you send it to the client: