How can I tell my daughter to stop shopping so much?

I'm not the type to confront people. I allow things to happen for as long as they are reasonable. So yeah, I barely say no to my family. But I'm very keen when it comes to saving money. I'm getting concerned about my daughter's shopping routine. She goes around and blows her bank account. She is not careful about these shopping sprees and ends up spending too much. We still give her money in addition for her daily expenses and she has her own salary. I understand that she's earning quite low so I don't get why she shops so much, too much actually. She ends up asking us for extra money. I always bring this up to my wife but she never does anything about it. I have also told my sister, since she's very close to my daughter, to help me in talking to her about the need to save money but my sister is too busy with her international dating blog events. I'm getting so frustrated because I have no idea how to confront my own child about her actions. I need advice for this. Don't know what to do.