My daughter is 38.5 inches and weighs 32 pounds, we took size 3 and they fit well at first but then the waist stretched a little. Maybe 2t would fit better. She hasn't worn a 2t in over a year. The black doesn't show through, but they're not as thick as the Target leggings. They have a great true Capri length. I don't think you should go up a size, I would stick with your kids normal size or even a smaller size if you usually order a size up. I don't feel like they're going to be huge, just a little big. Update: It's been 5 months and my daughter is now 3 years old (size 4t) and the 3t leggings fit perfectly! These are good leggings, I would recommend them! They have been washed and worn decently. They shrink a little with washing, but not much! I've upped my rating to 4 stars because they're holding up pretty well. They're a little thin, but that wasn't a problem.
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