GELUKSDAL, South Africa (AP) _ For Sandra Laing, the repeal of the last major apartheid law came too late.

Because she has slightly darker skin than her family, Ms. Laing's race classification was changed from white to mixed-race under the Population Registration Act, which Parliament repealed Monday.

As a result, she says, her life was irrevocably altered. Her education was disrupted, she was shunned by her community and her home life was broken up.

Now a 35-year-old mother of five, she says she has not seen anyone in her family since she was 16 and has no idea where they are.

Her world began to unravel in 1966, when police fetched 10-year-old Sandra from a whites-only school in Piet Retief, 185 miles southeast of Johannesburg.

She said they told her not to go back because she was not white. She does not know why she was expelled, but under apartheid laws people of darker skin were often denounced anonymously to the authorities.

Many people in the apartheid years saw their lives collapse after they were denounced to the authorities and their racial classification changed by classification boards. Government boards often used the ''pencil test'' in which a pencil was put in a person's hair to determine their race. If it didn't fall out, they were classified black.

Ms. Laing said in an interview that she didn't care at the time ''because I was small then. ... I was just upset because I had to leave school.''

While her honey-colored skin was always darker than that of her family, her birth certificate said she was white.

But after she was removed from school, Ms. Laing was ostracized by her white neighbors and remained at home the next two years.

Her parents never explained why her skin was darker than that of anyone else in the family, she said.

Shunned by whites, she said she played with black children. She said she became accepted by them and was more at home with blacks.

At 16, she fell in love with a black man, Petrus Zwane, and moved in with him. She said she has not seen her parents since.

''My father was angry. You know at that time they were very against the black people,'' Ms. Laing said.

Her father died in 1988. Her mother writes her but does not include a return address, she said. Marriage or sexual relations between whites and blacks are rare in South Africa and strongly disapproved of by most whites.

Eleven years after first being shunned as a non-white, Ms. Laing needed a state identity document to search for a job. She was formally reclassified as ''colored,'' or mixed-race by the government on the basis of her skin color and the earlier explusion.

An official was sent from Cape Town, and without talking to Ms. Laing, he signed the form that officially changed her race, she said.

Ms. Laing said she could not find work for many years. Eventually she broke up with Zwane; she said their three children were placed in welfare.

She now lives in a simple three-room brick house with her other two children and their father, Johannes Mothaung, in Geluksdal, a rural, mixed- race settlement 30 miles east of Johannesburg.

Ms. Laing says she is not bitter.

''I have somewhere to stay and someone looks after me,'' said Ms. Laing, who is unemployed.

But if not for apartheid laws, Ms. Laing believes that ''I would have gone on with school, perhaps I would (have been) with my parents.''