She is the youngest of nine children, with six brothers and two sisters
Her father died in an accident when she was 15 and her mother is a retired nurse.
Semoko matriculated from Lofentse Girls High School in Orlando East, Gauteng, then completed a BA Hons Degree in Dramatic Arts and Diploma in Cinematography at the University of the Witwatersrand
She got her acting start in Maishe Maponya’s stage production of the Lorraine Hansberry play A Raisin in the Sun.
She has appeared in the television series Justice for All, Young Justice and the sitcom Going Up
She has been playing the Ma Agnes character since 1998
She won the 2007 SAFTA award for best Actress in a TV Soap for her role as Ma Agnes Matabane.
Keketso is also a producer and writer on the Ulwazi Educational Radio Project.
She cites Mary Twala, Nomhle Nkonyeni, Cicely Tyson, Sydney Poitier and Morgan Freeman as her most inspirational people
