She worked in the County Courts Division of the Lord Chancellor's Department and at the Benefits Agency as an executive officer for many years.

[1][better source needed] Mrs Thomas is a campaigner for carers' rights and a past member of the Lord Chancellor's advisory committee.

She later served in the same position on Neath Port Talbot County Borough Council following local government reorganisation in 1995.

[9] She was also appointed in December 2003 by the First Minister Rhodri Morgan, to chair a review into safeguarding vulnerable children in Wales.

[14] In the Fourth Assembly, she held the position of Deputy Minister for Children and Social Services, with her responsibilities amongst others being childcare, child trust funds and parenting programmes.