Statutory Maternity Pay- penalising us for one ill month?

APO_Buddy

My first time posting- hope this is the right place for my query!
My Wife started maternity leave on the 1st of this month. Her pay is c 45% lower than her regular income.
My Wife works part time, and has earnt between £905 and £1,050 each month this year- except for June, where she only earned £548. This was because I was ill with pancreatitis and spent 20 days in Hospital. My wife took time off to help keep the house running, look after our 2 small children etc. 
We have spoken to her payroll today- who basically said that her 'average weekly pay' is based on the relevant period, which covers May and June. 
So basically her average weekly pay is May's Pay (£1,016.73) + June's Pay (£548.23)= £1,564.95, then divided by 2, multiplied by 12 and then divided by 52- £180.57- so she will get c £650 each month. 
This feels unfair, because she will lose out c £150 each month- for 9 months- because of one month where she didn't earn as much. 
Payroll are not helpful- shrugging their shoulders saying this is what the computer is telling them.
We don't disagree with the figures- but surely they can use a different 'relevant period' if the one they have is not representative of her actual average income? 
Has anyone had something similar- or is it a case of accept it and move on?
Many thanks

Penguin_

Payroll are right in so much as it is calculated automatically by their payroll software, they simply enter the dates.

If you don't agree, use the following link & enter the relevant dates & amounts:

Check if you can get Maternity or Paternity Leave or Pay, or Maternity Allowance - GOV.UK (www.gov.uk) 

chrisbur

Provided that the details from the MAT B1 have been entered correctly ( You can check using the link above from Penguin ) then that date will give the earnings period that has to be used for SMP.  The employer cannot use any other period.  They can pay more than the SMP calculation if they wish to but any extra must not be used in the figure that they reclaim.

EDIT  You say "This feels unfair, because she will lose out c £150 each month- for 9 months- because of one month where she didn't earn as much. "

Is the employer paying the 90% SMP for the full 9 months to their employees rather than the required £184.03 after the first six weeks?