DisneyKids Girls' Frozen Anna and Elsa Character Printed Waterproof Easy-On Rubber Rain Boots (Toddler/Little Kids)

If your child is a size 7 1/2 should I order a 7 or 8 because some reviews say it runs big.

Do u keep these boots on or take them off?

Talla ideal para una nena de 4 años?

My little girl is 3. Im not entirly sure what size to get her tho. I believe she wears a size ten and i dont see that size on this chart..help?