Is it normal to not like your sister

My sister and I are 6yrs apart. Im 20 shes 14 and we dont get along AT ALL!!! Ima Cancer she's a Aquarius((not big into horoscopes but alot of ppl say thats why we dont get along.)) I lovvve her to death I would do anything for her but I dont like her. She has the WORST attitude that i have ever seen. She's always angry. Shes ;azy and selfish. She dont clean up she dont listen to nothing my mother says all she do is sit around the house and watch tv all day...unless shes getting something out of it. If my mother says that she will give her money or a gift then thats the only time she cleans up or listens but as soon as she get it she's backl to her normal self. Its to the point where no one wants to be around her. My mother is very sick so she cant really discapline her like she did me. My mother cant get upset cuz then she starts throwing up blood her pressure goes up and she has to be admitted in the hospital so i try my best to do whatever I can to keep her calm but my sister dont care. she does things to make my mother yell and get her upset. Shes very disrespectful she lies all the time and shes dirty. I use to go out and buy her clothes and shoes every friday because I always wanted a lil sister. I always thought sisters should be bestfriends and we were when we were young but for the past 4yrs we just been bumpin heads. I use to try and get along with her but she only nice when se think someone is buying her something. For one thing she's too grown and I see that she's a lil lost in life so I try to help her out but she always bring out the attitude. I feel as though I should be her role model and I am I see that she wants to be just like me and I try to help her but it gets me nowhere. Now shes going to hs this year and I always pictured that we would be going places and hanging out. Shopping in the malls together, going to get our hair and nails done together, movies, dinner, calling eachother and talking on the phone...things like that. But were not. I would rather hang out with my sister than my friends but her attitude makes me dont even wanna be around her. I try to make my day as busy as possible just to not be around her. Me and my mother are bestfriends and we get up early in the morning and leave her home just to be away from her so that we dont get stressed out.
I kno it hurts my mother to see her only daughters fight everyday so I try not to but i just dont like her. i feel bad because of that...is this normal??