My mom lives her life high. I beg her to stop but she doesn't listen, what should I do?

I am a 14 year old girl. I live with both parents and my 16 year old brother. I love my family but we have alot of problems. My main worry in life is my mom. She is my everything. I have NO idea what I would do without her. I don't even what to think about life without her. She is only 49. She has a job as a house cleaner and my dad is a firefighter. There was a legal herb going around workhis work that could get you high. He got hooked on it so he started to do it around my mom years ago. So maybe 5 years back my mom started to do it with him. I didn't know until I was about 11. I knew what she was doing everytime she said she was "Using the restroom". She would Lock her door, I would her the lighter light, and then coughing. She always sprays vleach after to get ride of the smell. But I can always still smell it. She lied about ti to me for years. l confronted her about it last year. She began to "use the restoom" every couple of hours. My dad still did itbut not near as often. The promised on new years eve it would be that last night but my mom still does it. I beg her and cry to her to stop. She says I am. I am. But she never does. I hate it. My mom is always high. Not in a bad way like loopy crazy party way, just in the fake happy way. She doesn't drink or party she is such a good mom. But thats her flaw. A very bad flaw. They just made the herbs ilegal in kentucky. But she still orders ofline. I can't stand it. I feel like she hates me and her life and gets high to be happy. Someone please help me. I can't stand it she is killing herself and our family.