Most of the clothes I own are modern clothing from fashion in the last 10 or so years. My kid clothes are what kids wore when I was a kid 15 -20 years ago. My adult clothes could be worn by women today (if they like wearing skirts and dresses). Basically, I need clothes/outfits that I can imagine girls actually wearing in real life.
I wish I could have authentic clothes from other time periods, but they need to be as authentic as possible. For instance, I did wear a 50s housewife costume, but it just didn't feel right. I also owned a medieval princess costume, but again it didn't feel right. Just like how when I wear school uniform, I need branded authentic clothes that students of that school would actually wear, not unbranded (barring stuff like the skirt/shoes etc) or costume pieces.