Is me or does my sister get off on other peoples pain?

so my sister is older than me, long stoy short she was a runaway kind of a kid whoe eventually got raped at a party and fully ran away after that, then i was born. she came to this country. when i was 7 came too. she was amazed at how well me and mom mom got along (or so i suspect) she ws immediatley very mean, adding all the little and sometimes really big things she did to both me and my mom. my mom actually feels guilty because she thinks she was a bad mother with her so she kept trying to go back to he dragging me along with her. i began to change over the periods my mom called it quits and got away from her only to have her come back later. again the point is i began dressing really conservative. for some atrange reason after loosing her kids and getting pregnat she got maied and became a church going woman. i still dint like her but my mom fell like butter on the pan. as they got closer things sort of came up but once they got into another fight my mom finally tld me about these little comments of hers: that i muts of been raped because i dress this way (jeez what a low) that im spoiled because im shy (she hates me so she cant possibly be actually worried so come on) and so on. one morning during one of their akwar make up breakfasts my mom commented to my sister a questions i had about certain LOVE thingies and my sister just shot a bunch of info my way amongst which was :yu kissed your cousin when you were smalland alllot of other disgusting things leaving me dumbfounded the worst of all is that when my mom came to my room she said all she had said were lies. like what the F who sais lies in front of some one else? and my mom jsut went back to my sister liek she hadnt done anything and insisting she had just been lying and beleiveing herself. do i or do i not have reasons to be pissed off at both of them? who is right in this situation? thanks for your opinio