Alcoholic sister

I am overwhelmed with grief. I feel like no.matter how hard we try it will.never feel like we did enough. I have an older sister snd a younger sister. My younger sister is 28 years.old and has been a full blown alcoholicfor maybe 6 years now. Drinks all day every day but shes a functioning alcoholic. She has lost her house never paid bills, horder. Has 2 small children and drives in the car with them and she drinks while she is driving. For years we have all tried so hard to get her to go to rehab and she denies the addiction completely. Our mother begged her to stop drinking before she ultimately passed away last year and she still wont stop. She askes ym older sister for money every hour.of the day. " can you send me 10 bucks so i can feed my kids" " can you send me gas money so i can take my kids to school". My older sister officaly and finally blocked her after sending 1000s a month to her. My dad is a retired army vet and firefighter let her and her 2 children stay with him. He worked his ass off his whole life to.finally get to retire. And he helped her get a job, a car and tried so hard to get her on her feet. She wrecked his car twice. And destroyed his very clean and comfy hoke. Hording toys bringing stuff in smoking cigarettes when hes never smoked a day in his life. She had his window sill covered in cigarettes. 3 whiskey bottles in the trash can and he finally had to get another job to pay for things since she was living there and not pitching in. He had one thing that he loved dearly. It was his precious cat that loved him so much. She would leave his doors open cause her and the kids woudl go in and out in and out. His cat got.lose and has been missing for 2 days. He kicked her out. Hes almost 70 years old he doesnt deserve this. Anytime i bring up rehab i dont hear from her. It hurts. It hurts so bad i feel like this is it. Ive lost my little sister. Im a nurse ive watched people die from alcoholic cirrhosis. Ive begged her to stop. I told her i would watch her kids while she went to rehab. Nobody wants to help her now. Has anyone gone through this. Update: she just texted me and said " man i dont have aplace for.my children to sleep tonight" it hurts to ignore this text. Thats my sister those are my nephews. But if i let her come..she will never leave and she certainly is not allowed to drinkat my house. This is aweful