Question on Holiday entitlement for those on unpaid maternity leave

Under the law the calculation is 8% of their hours worked during the year, not earnings, to be paid "at the normal weekly rate or, as the case may be, at a rate which is proportionate to the normal weekly rate". If she normally works 20 hours a week (during weeks when she isn't out on leave) and is paid €20 per hour, under the 8% method of calculation she'd be entitled to 83.2 hours of annual leave per year to be paid at €20 per hour of leave. Weeks during which she is out on maternity leave are generally treated as though she was employed and working her normal weekly hours for the purpose of calculating annual leave entitlements.

She is also entitled to benefit from any public holidays which fall during her maternity leave, so don't forget to include those in your calculations, however you are handling them (e.g. as an additional normal work day's pay, or an additional day's worth of annual leave).