This might just be a phase...It's kind of common for some girls to like to wear t-shirts & baggy jeans. I used to do that when I was 10 (but I didn't object to wearing sleeveless dresses.) but when I was about 11-12, started getting more interested in skinny jeans. xD The main reason why I dressed in baggy clothes all the time is because I thought that it was just more comfortable. Of course, I didn't really care much for what I looked like then. Well, I was quite a tomboy back then. I think it's best that you let your daughter dress up how she wants to and not give her a hard time about it. That will just make her feel worse, that's how I felt when I my mom always went crazy about what I wear to school..Of course, she was more worried that I would get teased, although I never did. But what I do think is unusual is that she doesn't like to wear her socks and the wearing her underwear inside out. I think you should go see a counselor about this, because there could be a little something going on. Also, I've heard that some autistic kids have trouble with clothing tags rubbing against their skin...That could be something to think about with the inside-out underwear and how she says her clothes "don't feel right." Because I've heard that they just can't stand the clothing tags...Even if your child isn't autistic, it is still possible! And remember, as I said before: I think it's best for you to go see a counselor just to make sure something weird isn't going on!
Is she sensitive to outher things, i.e. textures, light? Some children have sensory disturbances, they tend to complain about "feel" of clothes........My son is the same about the tags, but it is opposite with clothes - he will not wear anything unless it fits him very well (he is very slim). He is 4....He is super picky about his shoes
Just let her pick her own clothes and do not pay too much attention to it - and it will pass....Let her pick it the night befor and allow enough time to get ready - my lil' one resists getting dressed when we are in a hurry, he like to have his breakfast in PJ's on his own sweet time:)
Good luck
What is her behavior like the rest of the day, could be she is hard to get going in th e Morning, so get up earlier ,a lot of children hate to be rushed around and need to take time , also a lot of children wear their clothes big, have you seen the boys with huge baggy pants, if she is overweight there is another reason as they feel the "big' clothes hide their being overweight.If she wants to wear her underwear inside out , how does that affect you, let her decide how she wears her clothes, take a step back and dont feed into it.you dont say how old she is, let her make her own decisions.No Disorder ,simply a child trying to assert herself.