If it’s a leo they wear for 2 years, I’d order up, but that’s just me. (I’ve sized gymnasts for years. If it’s a 1-year fit, it should be almost like a second skin, but if it’s a 2-year fit, you need some growing room). Torso length would concern me, because if it’s too short, wedgies and front wedgies, as well as going too high on the hip, are valid concerns. Plus, she will be uncomfortable the entire season. Armpit fit is another concern. If the torso is too short, it will pull at the armpit area, causing it to rip or hindering her ability to stretch up completely. I feel like torso length is probably the most important thing to fit well, because long sleeves are always too long and can be pulled up, girth (around the middle) will be snug any way, but torso length is where growth mostly occurs.