I ordered size 6-8 for my 8 year old son as he has skinny legs. The heels were half on the feet. These socks are for children aged 6+. They are too small for an 8 year old. They mostly stayed, but the heel kept slipping.
Pros
These are a bit small. But super cute. They shrink and dry a bit after the first wash.
Cons
Although a seamless sock design is desirable, they lack a non-slip grip on the bottom, which can lead to slip and fall accidents in toddlers who are still learning to walk.