If your sister is over state pension age, she should contact the Pension Service on 0345 606 0265 to check what she can claim.
She may be able to increase her basic state pension by using her husband's qualifying years if she doesn't already get the full amount.
If she is under the state pension age, her husband's qualifying years will
be included when she claims her own, provided she hasn't remarried or formed a new civil partnership in the meantime.
Depending on her circumstances, and the level of National Insurance contributions made by her husband, it is possible that your sister could be entitled to other bereavement benefits including a one-off bereavement payment, bereavement allowance for one year or, if she has dependent children, widowed parent's allowance.
The Bereavement Service helpline can also be contacted by calling the phone number above.