Need advice: Feel sorry for my sister and I don't know what to do to help her.

Need advice: Feel sorry for my sister and I don't know what to do to help her. So I'm 24 and my stutter is very mild compared to my brother and sisters. My brother is a year younger than me, and he can barely talk😢. My sister is so smart, like best at her school, still just grade 6, though. she just started stuttering maybe 2 years back, and it's gotten worse. It breaks my heart seeing how my life is already impacted by my stutter by declining opportunities becoz of my condition. I can't imagine her with hers being worse. She recently told me that when it's reading class, she reads from behind a door because it improves her speech. How do I help her, and are u guys in a similar situation like mine of feeling sorry for those with a stutter. I don't ever want kids man coz my heart would break hearing my child struggle to talk because of me. parents, siblings how do u cope?