can someone please give me advice

my mother if hooked on heroin she keeps saying she isn't doing it anymore but I'm always finding needles my sister has also came to me asking me what they were and etc. she tries hiding it from us she also never feels good , complains about always being sick , having sinus infections but will never go to the dr 🤦🏼 she works and stuff and she's doing better than she was when I was a child I just know she could do better I don't want it to kill her....but I don't know what to do