My sister needs a wake up call

But I don’t know how, she got together with a man a week after knowing each other, she was 23 and he was 20 they got pregnant that same month living together, now let me tell you that guy worked at the time 2-12 pm and when he comes home he would play PlayStation up until 4 am so the rest of the day he’s asleep, my pregnant sister didn’t had a car so he will take his to her appointments but she wanted him to go with her, so he would say shit like no I don’t want to or I want to sleep leave me alone, go by yourself, she felt sad about it, I went with her tho, she would go grocery shopping by herself and every weekend on his days off he would rather play games than going out with my sister so she would come to my place, when the baby was born I told her she can recover at my house since she didn’t had help, literally, to my surprise her bf let her, she has a c section on New Years 2019 on January 4 she was discharged and came to my house but in 4 days she told me it was time to move back to her house and I said that’s too early she couldn’t even walk well yet, she said that the man wanted to see his child and misses her, when she took a shower that same day her bf called her but I didn’t answered her phone, I saw the text messages they had between them and my sister was the one that texted him saying she missed him and even send him pictures of the baby but he never replied anything back, and I thought oh maybe they talked through the phone, well she left only 5 days staying with me, when she got to her house she immediately called me saying that her bf wasn’t helping her with the baby and that she needed to eat but he will demand her to cook food to him, she wanted to come back but he didn’t let her, well all 2019 was the same she would take the baby to the appointments by herself, go grocery shopping by herself and not only that he would tell her to not buy stuff she likes to eat because it’s bad for her like soda and chips like wtf you don’t tell a person what to eat or not, well now it’s 2020 and he still the same looser every day is something new but when she was at the end of her pregnancy she stopped working and when the baby was 10 months old he told her that is time to go back to work, mind you, she doesn’t have a car, or a babysitter since I have 3 kids and a newborn so I couldn’t help her, but she goes to work by foot everyday from 4-12 pm, I have no idea if he picked her up or she walks home but it is far away, that’s a 12 minute walk, it bothers me that he can even take the car to her when he started working from 8-5 pm he can leave the car there and he can walk home that way she can come back with the car but he’s tired so he can’t do that 😒, she now tells me that theres no food on the fridge and that he’s tired to go grocery shopping, I told her why is she has he own money, well her dumb ass put his bank account info in her work application when she applied and now she can’t even have her own money, he “lost the card” so now they don’t have “money”, there’s ways to fix this but my sister is afraid of him, she can’t tell him anything because he gets mad and she gets scared, I don’t know how to help her, I have given her advice on how to get her money back but she needs money on her bank account in order to open one but he doesn’t want to give her the money. It pisses me off I have spoken to get telling her if she’s willing to just leave him and she doesn’t answer me, I know she wants too but she doesn’t know how, I don’t know to either , she doesn’t get physical abuse but mentally abused. If anyone know what to do please help us