Kids Crocs - Athens sizes

[alisonbestford]

DD's Crocs Athens have just 'bitten the dust'

We bought them in Orlando, last year, and they are kids size 12/13.
I'm about to order her a new pair, from JellyEgg, but anyone have any idea what size I should order?

She's a 13 and a half UK size.
Would you think the size 13/1

Thanks