i'am the big sister do i really have to shoulder what my little sisters needs?

Just because you are the oldest does not mean that you have to shoulder everything . They have to learn to grow up sometime and you can't be there to do everything for them all the time as this will cause them to be lazy and like you said you have your own life to live . Have you tried talking to them and telling them to try and figure things out on their own that you are there for them but you would like them to try first and then if they really can't do it then you will help ? I grew up believing that because I was the oldest that I had to do everything for my sister and when she would do something wrong I would take the blame so she would not get in trouble . Today we don't have anything to do with each other becasue she is really not a nice person to be around and I often wonder if this was partly my fault for doing everything for her . Not that I am willing to take all the blame as she is an adult and very much capable of accepthing her own mistakes , she just doesn't .