Is it not the case that many years ago, a considerable number of married women who were in employment at that time only paid an employees lower state pension contribution rate applicable to their marital status and many of these women only now receive a lower rate of state pension, not haven taken the opportunity in later life to pay extra contributions to bring their state pension rate to par?
I think the most common situation I come across amongst women of a certain age is that they worked from around 16 to their mid-20s, then raised a family for 20 odd years before finally maybe doing a bit more work from their mid/late 40s through to retirement age at 60. Often the later jobs might be part time not full time and/or not permanent posts so ended up with periods of unemployment as well. All of which added up to not having a full contribution record so missing out on a full state pension.
Those women (along with those in your situation) if they are single for whatever reason are well advised to claim Pension Credit which will immediately provide them an income of £167.25 per week no matter what their State Pension actually is (along side no longer having to pay Council Tax, potential not having to pay rent anymore, as well as for over-75s getting a free TV licence).