Cyflwynodd Kirsty Williams AC yr hyn a fyddai'n dod yn Fil Lefelau Staff Nyrsio (Cymru) ym mis Rhagfyr 2014 fel Bil Aelod Preifat. Gyda chymorth Llywodraeth Cymru, cafodd y Ddeddf y Cydsyniad Brenhinol ar 21 Mawrth 2016.
Kirsty Williams AM introduced what would become the Nurse Staffing Levels (Wales) Act as a Private Member’s Bill in December 2014. With the support of Welsh Government, the Act received Royal Assent on 21 March 2016.