I'm thankful for your concern, and I urge you to help your daughter be wise in the way she dresses even at the risk of being called old-fashioned!
Teenagers don't always realize why they do the things they do but one of their most powerful motives is the desire to be liked by their peers. No teen wants to stand out from the crowd or be thought of as odd or out of step including in the way they dress. Parents need to understand this and sometimes they need to step in and help their teenager understand it also so they can resist harmful pressures from the crowd.
Teenagers also may not realize what signals they are sending to others by the way they dress (particularly those of the opposite sex). One of your responsibilities as a parent is to help them understand this. If you don't, they may find themselves on a path they never intended to take one that even leads to disaster.
Pray for your daughter and pray too that God will give you wisdom as a parent. Most of all, urge your daughter to give her life to Christ. Jesus said, "I have come that they may have life, and have it to the full" (John 10:10). Only Christ can help her become the person God wants her to be.