What is going with my music since ios 7?

I just got the new ios 7 update on my ipad and I don't know whats going on with my music. I share an iTunes account with my sisters so I automatically get their music downloaded onto mine because of cloud. I had deleted most of their music because I don't like it and everything was fine. Now with the ios 7 all of their music is back and I can't get rid of it! It's not technically downloaded because there's still a button I have to press for iCloud but the song will still play when I tap it or hit shuffle... I'm sorry that's a horrible description but I don't know how else to word it... How do I get rid of their music on my ipad?