SockShopBoys and Girls Plain Bamboo Socks with Comfort Cuff and Handlinked Toes in 3 Pair and 5 Pair Packs

Size 39

Hi my daughter is 10 yrs old with a foot size of 3 what size would you reckon I should buy? I brought the up to 3.5 sock but they just look to small

Are these stretchy/soft around the calf? My son has very wide calfs.

Is there a seam at the toes or is it a hidden seam? Thanks