But she did not fit into the "fiery" left-winger stereotype in her years as an activist and eventually president of the old local government union Nalgo (National and Local Government Officers' Association). Smith was never considered completely "on-side" in the trade union sub-culture - her views were a touch too right-wing for most of her colleagues - but she was never a Conservative.
She was associated with the outer fringes of the Labour Party in her younger days, but, if she was ever a member, none of her colleagues knew. When, in 1981, the "Gang of Four" established the Social Democratic Party, they counted Smith as one of their supporters. If anything, that was worse than being a Conservative to many trade unionists. Even right-wingers in the Labour Party, who might have privately toyed with the idea of joining the SDP, felt themselves forced, in public at least, to distance themselves from her.
To complicate matters she launched a movement within Nalgo that was erroneously seen as the brainchild of the Far Left. Sheila Smith was one of the principal forces behind the notion of "self- organisation" in Nalgo. This was a movement within a movement which spawned pressure groups to promote the rights of women, ethnic minorities, gays and lesbians, and the disabled. One of her long-term aims, of securing a strong female representation among full-time officials at the top of the union, has never been completely realised.
Her enthusiasm for the project was borne of a deep feminist conviction which brooked no argument. She accepted that to campaign in support of a structure dedicated to promoting the rights of women, it was logical - and just - to extend that opportunity to other people whose lives were blighted by discrimination and prejudice.
In fact the policy of self-organisation prompted a rash of "loony left" stories in tabloid newspapers and proved, often quite usefully, to be something of a thorn in the side of the permanent officials.
The daughter of a milkman, Smith was born and brought up in Stoke Newington, north London, and educated at the Skinners' Company's School for Girls. She joined Nalgo in 1951 and held many union positions including president (1969-70) and chairwoman (1972-77) of the branch representing the Greater London Council and Inner London Education Authority. She also sat on the women's rights committee of the southern region of the TUC.
She was a member of Nalgo's national executive and sat on several key committees including that concerned with equal opportunities. Finally, in 1986, she was thrilled to become president of her union, only the second woman to hold the post.
She opposed the creation of the public service union Unison through the merger of Nalgo, the National Union of Public Employees (Nupe) and the Confederation of Health Service Employees (Cohse) - but the movement towards amalgamation became inexorable, and Unison was launched in 1993. Smith contended that the other unions were less democratic than Nalgo because they were dominated by full-time officials rather than lay members like herself. She also argued that the political fund of the other two organisations, which were affiliated to the Labour Party, would eventually dominate the non-aligned fund of Nalgo. Thus far this does not seem to have happened.
Sheila Smith was a heavy smoker and in her later years suffered from emphysema, as did her father. Towards the end of her period as president she was extremely short of breath because of her illness and only willpower kept her going.
Smith dealt unceremoniously with those with whom she disagreed, but she leavened her occasional stridency with personal kindness and a sense of humour.
Sheila Kaye Smith, trade unionist: born London 16 December 1932; President, National and Local Government Officers' Association (Nalgo) 1986; died Hemel Hempstead, Hertfordshire 14 October 1998.