Williams was born in Taunton, Somerset to Welsh parents, whilst her librarian father was working there. After moving to Liverpool, in 1974 the family moved to the village of Bynea, Carmarthenshire, where she grew up. Educated at the independent St Michael's School, Llanelli, she then graduated from the Victoria University of Manchester with an honours degree in American studies, including a period studying at the University of Missouri. She then returned to work for the learning resources department of Carmarthenshire College in Llanelli, before taking up a post as a marketing and public relations executive for a small business in Cardiff. She is married to a farmer; the couple have three daughters and live on the family farm outside Brecon.
Political career
Williams joined the Welsh Liberal Democrats at the age of 15. In the 1997 general election, she contested the constituency of Ogmore, coming third. For a long time she was a keen advocate of a Welsh Assembly, and she campaigned hard in the 1997 referendum for the creation of the National Assembly for Wales. She was subsequently appointed to the National Assembly Advisory Group by Welsh SecretaryRon Davies. She was elected as an Assembly Member of the National Assembly of Wales for the constituency of Brecon and Radnorshire in May 1999. In her first term she became her party's health spokesman. She also served as Chair of the Welsh Assembly Health and Social Care Committee between 1999 and 2003. In the 2006 Welsh Yearbook Political Awards, she was voted "Member to Watch 2006" In a poll at the end of 2006, Williams was voted "Sexiest Female Liberal Democrat" on Stephen Tall's Liberal Goes a Long Way blog. On 8 December 2008, Williams became leader of the Welsh Liberal Democrats, having defeated Cardiff Central Assembly MemberJenny Randerson. In 2011, as leader of the Welsh Liberal Democrats, she agreed to support the Welsh Labour Government's 2012–2013 £14.5bn Budget on the basis, amongst other things, of securing the Welsh Pupil Premium: an extra £20m to spend on the education of the poorest pupils. Teaching Unions welcomed the deal, with ATL Cymru director Philip Dixon saying, "Our children are our future and investment in them is investment for all. Labour and the Lib Dems deserve credit for ensuring that our children, especially those in most need, will now get a better start in life." In 2013, Williams and the Welsh Liberal Democrats more than doubled investment for the Welsh Pupil Premium in exchange for abstaining on the Welsh government's annual budget. Williams has gained a reputation for campaigning on health issues. In 2012, the Welsh Government agreed to take forward the Welsh Liberal Democrat idea of a Health Technology Fund to allow patients better access to innovative treatments. The following year, the Welsh Liberal Democrats achieved a further £9.5m investment into the Health Technology Fund as well as the establishment of a £50m Intermediate Care Fund to drive integration of health, social services and housing. Williams has been part of a long-running campaign for a law requiring minimum staffing levels for nurses in Welsh hospitals. In 2014, Assembly Members voted to allow Williams's proposed legislation on this issue to be taken to the next legislative stage. In December 2012, Williams won ITV Wales' Assembly Member of the Year Award in a ceremony at Cardiff's City Hall. In the Queen's Birthday Honours 2013, Williams was appointed Commander of The Most Excellent Order of the British Empirefor public and political service. In the elections to the Welsh Assembly on 5 May 2016 Williams retained her Brecon and Radnorshire seat with an increased majority. However, as the sole Liberal Democrat representative in the new Assembly, she stood down as leader of the Welsh Liberal Democrats the day after the election. First Minister Carwyn Jones appointed her to the Welsh Cabinet as Education Secretary; 31 seats are needed for a majority in the Welsh Assembly, Labour had 29, so Williams joining with the Labour administration created a working majority. On 16 June 2017, Williams once again became leader of the Welsh Liberal Democrats, having been chosen to do so by the outgoing Leader of the Liberal Democrats, Tim Farron, after the defeat of the previous leader of the Welsh Liberal Democrats, Mark Williams MP, in the 2017 general election.