Is it normal i'm uncomfortable with the way my sister dresses?

I don't want to call her names but it's hard not to think of the way she dresses as slutty. Almost everything I've seen her wear has made me uncomfortable. If she's feeling modest, she'll wear a spaghetti strap shirt or tube top. But she seems to prefer see through mesh shirts and fishnet tops, which defeats the purpose of wearing shirts in the first place because it's not even hiding what's under them. The places she buys clothes from calls it club wear but she wears it almost all the time. For bottoms she wears spandex and short shorts. I'll see her in regular pants instead if I'm lucky. If she has to be formal, she wears dresses that are the absolute shortest length they can be while still being considered dresses. The only dress she has that isn't super short has a side cut that goes all the way up to her waist. If there won't be family, she'll wear a dress with a plunging neck line. One dress of hers I've seen isn't a dress so much as what looks like a ribbon that wraps around her neck and drapes over her boobs and leaves the rest of her upper body uncovered.

It breaks my heart that this is the way she wants to get attention. I don't feel like I have the right to ask her to change, but it bothers me that everyone she walks by on the street gets an eyeful of her. It's sad to see her come home dressed like that and think that's how everyone saw her. It makes me awkward too. Once I was with some friends and she was picking me up. She came and got out of the car to get a drink before taking me home, I said that's my ride. A friend said wow, looks like someone's getting lucky tonight. And I said actually that's my sister. He looked surprised. Then he said I'm lucky I have a sister who shows herself off and dresses confidently like that. I said no, I'm really not but maybe my friends are. He apologized and admitted that was a messed up thing to say. She got her drink, came to me greeted me with a hug and said lets go. I went to her car with her and not all of my friends overheard the conversation I had with my friend because some were giving me a "hey, looks like someone's about to get laid" look. I think you know what I mean. They assumed because of how she dresses that she was doing it for me and to be fair that is a normal assumption. But it's her choice how she dresses and even though I want her to dress differently I don't think I can tell her to stop. I don't want her to feel like I'm repressing her or thinking of her in a sexual way, so I just pretend I don't see anything wrong with the way she dresses.