azndude: Congrats on coming out to your sister! Coming out to family is the hardest for a lot of people because they are the only people in your life that you can't just kick out of yours if they aren't supportive.
Be ready for a few reactions in the coming days. She may pull you aside and say she's totally cool, she may say she's not, she may say that she doesn't know.
Just remember that whatever she says or does in the coming days is coming from her really thinking about how she feels about sexuality as a whole. Whatever she says or does, she's saying and doing those things because she cares about you. (Even if her reaction isn't a positive one in your eyes, she believes that it will be good, supportive advice.) If it's a negative reaction, she's only reacting from what she knows and doesn't know. If it's positive, great!
Do'nt be afraid to ask her for confidentiality during this process either. It's not her news to share, it's not her conversation to have with others. In due time, you won't care if she says anything to anybody, but this is an important step for you, and she will respect that if you ask. She may not understand that it's something to keep between the two of you until you explain it to her.
Best of luck, keep us posted, and we're all here to give you advice or guidance if you need it.