Is it normal i love my stepsister but dont want to lose her as a friend

So, I love my stepsister, I known her for 6 years now, we weren't close at first but when we entered high school we started drinking and smoking together and just hanging out, I never relize that I truly love her until last weekend, she came up the stairs and just stood there for a second and at that time Carolina by parmalee came on, thats when it hit me, ever since that I cant stop thinking about her and I want to tell her I love her but I dont think she loves me and I dont want to lose her as a friend but I want to be more then friends. No we never had sex but we fooled around abit twice when we were drunk but nothing serious. So what should I do, and is it normal to love your stepsister