These are the benefits that depend on NIC contributions:
Contribution based Jobseeker's Allowance
Incapacity Benefit
State Pension
additional State Pension
Widowed Parents' Allowance
Bereavement Allowance
Bereavement Payment
If you don't pay Class 1 NI because, for instance, you earn below the threshold, you can pay Class 3 NI, but this does NOT give any entitlement to Contribution based Jobseeker's Allowance, Incapacity Benefit or the additional State Pension.
It may be that she accrues some benefit in Poland if she is paying NI in the UK.
KatyMac the link between NI and expenditure on the 'welfare state' no longer exists. NI simply forms part of the general pool of income to the treasury - seethis interesting chart.