NWOT Baileys Blossoms Mommy & Me matching pink leopard swimsuits size L & 6-9mo

Brand new, never been worn! Tags removed & bathing suits washed with baby detergent, hang dry. Suits did not fit us right. Baby swimsuit is size 6-9months but fits like a 0-3months. Website said to size up one.. I should have sizes up two sizes. Womens large fit weird on my body. Fits more like a medium with full coverage in the back.