Kids scarf

hey everybody,
i have been having great knitting success lately and have taken on making a scarf for my little cousin for her birthday in February. I have about a foot and a half done already, but i was wondering about how long you normally make kids scarves. She will be turning three, so i need it short, but i dont want to make it so short she will outgrow it right away. Thanks for the input!


I have heard that you make a scarf as long as the person is. So I would meaure how tall she was and go from there.