Speedo Training Swimsuit One Piece

I didn’t understand Speedo sizing when I bought this for my swimmer few months ago and now I can’t return it. Fits like girls size 10. My swimmers is a new 12yo and an adult size small - that’s how far off I was! SKU: 7719902 | Product Code: 8177416 The Speedo Women's Fierce Flow Flyback One Piece Swimsuit features powerful and durable Endurance+ fabric and an exciting print that stands out in the pool. Features One piece swimsuit. Fierce Flow / abstract print. Endurance+ fabric. 4-way stretch. Chlorine resistant. High leg cut. V-back, keyhole. Moderate bottom coverage. Details Fabric: 50% Polyester, 50% PBT. Care: Hand wash, cold. Line dry. Closure: Pull on Chlorine Resistant: Yes Back Style: V-back, keyhole Fit: Competitive Adjustable: No Bottom Coverage: Moderate Country of Origin: Imported