Our Pippa Bows are handmade from the softest most delicate fabrics and will stretch & from with your little girls head. - If your child is under 6 months, we recommend choosing size small for a nest fit. Size small will fit up to 18 months, if worn regularly enough as it will stretch & grow with your little girl. If you find it’s a little too snug, we recommend gently stretching it out with your hands. - When your child turns 6 months, we advise a size medium, as you don’t have the 6 months worth of wear/stretch. Size medium will fit up to an adult so have fun twinning with your little one. - Do remember...a size small will still fit a 6 month old little girl, it will just need a gentle stretch to catch up with the growth. - If you have some size small in your Pippa Bow Collection, don’t put them aside or let them go to waste, pop your hands inside & give it a little stretch.