Maternity leave and other payments

Hi my sister will be taking maternity leave in the spring, she works part time and receives FIS as well as a part payment of OPFA. does anybody know what way this will work when her baby comes? Will the OPFA or FIS go up and is there a minimum maternity benefit payment, presumably as she is working part time, hers would be quite low. Any help appreciated, she is worried about rent and bills at this point.

FIS can continue while your sister is on maternity leave - but only for the statutory leave (26 weeks). It cannot be paid if she takes additional unpaid leave from work.

From reading the information on Maternity Benefit, she may not qualify for the full rate (€230 from Jan 2014), because she is getting One Parent Family Payment. Maternity Benefit is paid at half-rate if OFP is in payment.
http://www.welfare.ie/en/Pages/mb.aspx

After the baby is born, she can apply for a review of both the FIS and her One Parent Family Payment. There may be increases in either or both, because of the additional child.

If she wants to make a specific enquiry regarding her possible Maternity Benefit payments (and how her OFP affects it), there's an option at the bottom of the page I linked to above to email Maternity Benefit section directly.