If I got custody of my niece and nephew would I get help money wise?

My sister, is 28 has already had 5 kids. The fist 2 were both adopted out right off the bat. The children's & family's services said she was an un fit mother. The next two she has, they are 7 and 5, her most recent son who is 8 months don't live with her, the grandma has custody.
With the 7 and 5 yr. olds, she doesn't take care off them right. She doesn't have a job, doesn't want to get one. She cons men she doesn't know to send her money. She doesn't clean her any house were she stays. And always getting kicked out because of her habits. And not paying rent.
She doesn't watch her kids or make them behave. She thinks she can buy them toys and that all she has to do. She don't show them love she buys them off. My 5 yr. old nephew got hit by a truck about a month ago, because she wasn't outside watching him, and he was playing in the street. But he is OK, thank you lord, he's OK.
They (7 & 5 yr. old) both still pee and poop in their pants and to bed, then wake up and run around naked while she sleeps. They don't get 3 normal meals a day, they eat junk food. And she doesn't make them brush their teeth. My niece already has an abess tooth, and my nephew complaing of tooth aches all the time.
My niece and nephew both also think that it is OK to go around hitting and kicking people.
They both rarely go to school and if they do they are always late.
So you see she is not the best of a mother. But when children services comes in, she acts totally different the complete opposite.
Now I want to fight for the custody, because she is currently in a homeless shelter, and I don't think they should grow up in a life style like they are.
Me and my husband both want them but we don't really have the money . What we were wondering. Is do you get assistance with money if you just have custody? Because that would be a great help. They would have all the love they need and the right up bringing. We would just need help with money. Would she have to contribute?

Foster care provide a monthly check for each child. It is not nearly as much as foster parents should get to provide for the children they are caring for, but it helps. Good luck