Please be careful to start your own thread in the future instead of introducing a new question into someone else's thread.
According to
Latoya Jackson's autobiography, her mother simply invented this name. It was very common in the African-American community in the 1970s and 1980s for new names to be created starting with the syllable La-. Ms.
Jackson's mother hasn't given any further information on how she created the name.
Toya is possibly a shortening of
Tonya, but
Toya has also been used as a pet form of
Victoria and Custodia in the Mexican-American community.