Complex sentence: Sparkle visits Sister in prison, and tells her about Dee getting into medical school, making Sister happy, who assures her that she'd be getting out in two to three years, and that she was clean now.
Split into simpler sentences: Sparkle visits Sister in prison and tells her about Dee getting into medical school which makes Sister happy. Sister assures Sparkle that she'd be getting out in two to three years and that she was clean now.