I agree. Sometimes you just have to deal with certain things. From the posts, it sounds like your sister is hearing and the vibrations wake her up? Or she's also deaf and the vibrations wake her up too. Either way, there might just not be a way around it. If you were hearing, and had a regular loud annoying alarm clock, what would the difference be? If you have to wake up for certain things, and you two sleep close enough that she wakes up, then maybe she should find ways to help her sleep through it, instead of making you find a new alarm. (Like earplugs, if she's hearing).
I mean, my roommates get up earlier than I do. I don't ask them to tip-toe around and not move anything because I might wake up. If they wake me up, I just smile because I get to roll back over and go back to sleep, whereas they're up starting their day. If the suggestions in here work, then go for it, but if not, then tell your sister to just suck it up, and at least be glad that she doesn't have to wake up so early herself. 
(Also, I agree with the "setting your body clock" idea that Missus_Philos0phyK presented. It does work really well. My uncle told me once that he never used to use an alarm, he would just make sure he knew what time it was when he went to bed, and would go to sleep telling himself to wake up at a certain time, and his body would pretty much always get it right. It's even easier if you just pick a time and get used to waking up at that time every day.)