They have wide feet and need the room. Kids age six and up should wear skates a half size smaller than their normal shoe size. Their toes should hit the end of the boot but not feel crammed in. Be sure the laces are tied tightly, but don't cut off circulation. Tie long hair back.
Long hair can easily blow in a child's face and obstruct vision.
Dress your child appropriately. Even if skating indoors, there is still a chill in the air, so dress children warmly and in layers. But keep the socks to only one pair. Two pairs make the feet feel bulky and they won't be able to feel the edges of the blade under their feet. Have skates sharpened regularly.