Complex sentence: Sepulvada's positive impact on Jones' life and career cannot be overestimated; she eventually cleaned up his finances, kept him away from his drug dealers (who reportedly kidnapped her daughter in retaliation), and managed his career.
Split into simpler sentences: Sepulvada's positive impact on Jones' life and career cannot be overestimated. She eventually cleaned up his finances, kept him away from his drug dealers (who reportedly kidnapped her daughter in retaliation), and managed his career.