I am working on a scrunchable scarf as part of a hat/scarf set for DotMom’s chemo kid KAL and am trying to figure out how long to make it. The hat is sized for 4-5 year old girl (I hope - no kids around to check it) and the scarf is 4" wide. I was thinking of aiming for about 4 feet long. Does that sound reasonable to those with kids? 
Length for child's scarf?
4 feet long would be a PERFECT length for a scarf for a girl that age.
Are you going to add any fringe to the ends? 
No - the main yarn for the scarf is white with a silver thread and I am doubling with a pink/purple varigated Fun Fur for 2" on each end. I think that seems fancy enough. The hat is out of the same yarn with Fun Fur included in the ribbed band and crown and a pom-pom on top.
On Knitty Gritty they say that if you want to make a scarf that raps around your neck and hangs down a little bit to make a scarf that is as long as the perso’s hieght. How tall is a 4 year old? That was 6 years ago for me so I forget.
How about a keyhole scarf? They are generally shorter, don’t fall off and would be harder for a 4 year old to loose.
Candice