How Do I Tell My Mom That The Guy She Is Talking To Is Fake?

okay well i have tried everything, but she won't listen to me. my grandma and aunts and cousins have even tried. she's just not listening to us. she meet a guy back in late december on Myspace [ keep in mind that majority of the people on Myspace nowadays are fake] and he initially told her he was in California , then they begin talking on Y Messenger, and he said he was in Africa doing business , saying that he owns this company in Lagos, Nigeria. Okay so she gave the address to where his company is suppose to be, and i Goggled it. Nothing Showed up! So fast forward to Feb. 2011 and he asked her for money so he could get to where she's at so he could assist her with bills and purchase her a new home and car and etc. eventually she ends up sending him nearly $2,000 and oh get this, she's on Disability so she doesn't work or anything My little sis stays with her and she literally starved her. Didn't buy any food for like 2 months. she's still talking to him today. and there's another guy that she's talking to as well. Met him on the same site and he's giving her the same Picture to look at when he's lying. he hasn't asked for money yet but i cant allow that to happen. She has to place our childhood home on the market and her and my sis are moving to the apartments! and if she doesn't pay her rent there, she'll be evicted and my sis will go into child services. I'm in no position to take my sis in and raise her cause i've just got situated with a job and all. please guys any help will benefit our family crisis :) xoxo! and thanks again Kristine