My little sister is fourteen, she's very beautiful but won't take care of herself. 
And I don't know why.

I have to force her to shower, brush her teeth, brush her hair, ect. 

Our mother works all the time as a bartender, so we rarely ever get to see her.
And everytime I try to talk to our mom about it  she says it's my problem! 

I try to talk to her about it, but she never wants to talk about it, one time I begged her to tell me what's going on with her but all she said to me is "im just tired." 

I feel like im doing something wrong.
I want to help her but I don't make enough money to get her into therapy.

I just want to help her. 

She won't ever go outside because shes scared of people trying to touch her, because she was molested from the age of six to the age of twelve. 

I don't know what to do, and im exhausted from my job, cleaning her and feeding her, taking care of our two dogs, and taking care of our mother at night when she comes back from work.