Hi,
Your wife is not entitled to credits for the period she had Married Women’s Reduced Rate Election in the same period where Home Responsibilities Protection (HRP).
HRP was in place from 06 April 1978 to 5 April 2010 and the rules for HRP clearly state that you could not have HRP at the same time as also having a MWRRE:
Home Responsibilities Protection: Eligibility
The link you mention below is for Parents and Carers Credits which started on 6 April 2010:
Reduced rate National Insurance for married women
HRP is different to Parents and Carers Credits which was introduced in 2010
Thankyou.