Hi there, Holly.

If someone makes changes to an Estimate, the QuickBooks Online Audit Log will track and display who made those changes, along with the date, time, and details of the edit.

The Audit log records modifications to transactions, such as estimates, as well as other activities within your QuickBooks account.

However, if you're trying to see who accessed or viewed the audit log, that information is not recorded within the Audit log itself.

Also, please make sure that you have separate account for your client, allowing you to identify in the User Column who has viewed the Estimate. 

If you have any further questions or need assistance, please leave a reply below.