Is it possible to do this and not ruin family dynamics?

I had a few things on my mind and would like to hear thoughts from this community. The only sister i have (18y) and I (22m) are both adults. So the question is not really a legal one, but more a social one. I feel like i'd love to explore this and find out if it's for me or not. But the problem is, if she's not interested, (i do have some indication that she might be interested as well but don't want to make a mistake and make her feel uncomfortable or weird about me), i would ruin the family dynamics and the relationship i have with her. I don't really want to lose my sister to a simple mistake. I do love her very much, but i also am attracted to her and don't want to miss the opportunity to find out if this is something for me. How do you think i should approach her? I would love to hear thoughts of women about this.