<human>: Summarize the given text in a few sentences.

Hello,

I could really use some advice Reddit. I have younger sister which is in that specific period of her life where she thinks she's smartest kid in the world, that she can do all by her self and doesn't appreciate anyone's good deed. She'll do anything to get what she wants and after that she forgets on all stuff that we did for her. 

Now I'm really sorry for my parents because (normally) they will do anything for theirs kid but since she is female, she is not doing any housework, she is lousy in school. 

I've tried to talk with her many times, and when I talk to her she understands everything and she agrees that she needs to change and needs to help to mother and improve herself in school but I think as soon as she goes out she forgets almost everything that I've been talking to her.

One more thing which I'm worried about is that she doesn't have some crew she hangs out constantly like I did, someone who knows my parents and Vice Versa. 
We are now in a fight and we don't talk because she told me that I ruined her birthday part since I wouldn't let her out because she came home at 3 a.m (plus she doesn't want to answer her phone, and that's usual stuff) and she went to excursion I didn't want to say goodbye to her.My father told me that she cried in a car because I act like so. 

I really would like to improve our relationship but I can not tolerate that kind of behavior. I think, because I'm older and mature person, I need to do something but I would like her to learn lesson and be more responsible but in other hand I am afraid of loosing her, since I know better myself and the fact that I will not let her act as she want.

Thank you
<bot>: I'm trying to help and direct my sister to right way but whenever it conflicts with something she wants I'm worst brother in the world