The answer to your question is not all widows are entitled to a widows pension, but the majority are. My own Mum never had a widows pension.
However, as the lady has an occupational pension the husband must have paid PRSI during his working life either in the Public Service or in private employment or self-employment. I would suggest an immediate application for a Contributory Widows Pension. The form can be downloaded from welfare.ie
If she over 66 she should also apply for her Household Benefits (Electricity, Telephone and TV Allowances) and if over 70 she may also be entitled to a Medical Card