My (26F) sister's (29F) boyfriend (26M) just broke up with her, moved out and left her and their 2 small children (f3 & f1) out of the blue. How do I support her through this?

My sister met said boyfriend when she was going theough a rough patch (I know, a recipe for disaster already) and they seemed like they really clicked and hit it off. My sister has had a rough time throughout her life; she has been burned by everyone shes close to (except for her family of course) and shes way too nice to say anything about it so people walk all over her. Litterally. Her boyfriend was making money, had a car, and was nice enough, and seemed good for her after her rough patch. Then she got pregnant soon after and they seemed so happy! I thought she was finally happy. Then after both the kids were born, he changed.To be perfectly Frank, my sisters ex-boyfriend is a fucking asshole. She's so upset right now understandably, but honestly he was kind of a dead beat. He barely worked. He never spent time with my sister. Ever. He spent ALL of his time in the garage doing whatever while my sister cooked, cleaned, bathed and looked after the kids. He didnt help with the kids barely. All he did was buy the kids stuff sometimes and thought that that was enough. Like NO! you have to emotionally be there for your family too, not just buy them stuff and think it's okay. They had to move back into my parents house because they were kind of struggling with 2 small children and trying to pay bills because he refuses to work and child care is freaking expensive!Anyways, long story short, they got in a fight because he was out all night and didnt come home till early morning (go figure 🙄🙄) and he left and never came back. This was on Sunday. He texted my sister today and said he found a place that hes moving into on October 1st.Shes so upset she wint talk to anyone and shes been sleeping ALL DAY. I tried calling her and she just hung up the phone and said I'll talk later. So my question is, how do I support her? Ugh I'm so sad for her because she thought she loved him but she doesnt realize that hes not right for her and doesnt treat her right.Sorry so long. Thank you for any advice. via /r/Advice https://ift.tt/2NnQk3n