My client's employees currently fill in detailed timesheets in QuickBooks payroll, where they specify what type of work they are completing for which client (they use the notes section to identify the client).
My client then repeats all the information from the timesheets in her invoices.
How can she use her employee timesheets to create invoices?
I have investigated the Weekly Timesheet time tracking feature and it will not help, as her staff need to track their start and finish times and time tracking asks for total hours only.
You are correct that the Weekly Timesheet feature only allows you to input number of hours worked. The best solution I would recommend would be to use TSheets to track the employees' time. In TSheets you can enter start and end times, and mark times as billable to create invoices.