Description call it a costume. Is it costume quality (fall apart within a few wears) or everyday use quality?

Hey, It is good quality, bought two for our girls, they use all the time and still in good shape. Would deff recommend 😊

Is this dress actually 100% cotton? Some reviewers said it's really made of polyester.

I am not sure, there is no tag on the dress that I could see. I didn’t check in the skirt area though. I also bought the blue one for my five year old granddaughter as well. The apron was definitely polyester, but the dress and bonnet seemed like it could be a cotton/polyester blend. You should know that both dresses were beautifully sewn and fit on the roomy side, which I’m okay with. Then they can wear them longer.

My daughter is 10 but very skinny. she is wearing size 9 slim in abercrombie and fitch jeans. she is 54 inches and 52 pounds. what size should i buy ?

I purchased size eight for my eight year old granddaughter and it fits well. She’s maybe a bit smaller than your daughter but not by much. I’d get a 10 and take in the sides.

Can a 5’3 13 year old wear this?

If the largest size offered is a 10-12 probably not unless she’s extraordinarily thin and even then the waist won’t hit her right. I’m 5ft and can sometimes wear a girls extra large which is usually a 14 or 16.