I had this problem with my 5 year old dd, except in reverse. I wanted to get her the beginner roller skates - the Barbie Fisher Price ones, because there's no way she's ready for real skates. But they only go up to a (US) size 12 and she's a 12.5. She did get them for her birthday, but they're not going to fit for much longer. Even now we have to jam her sneakers into them. She could really use a new pair of sneakers (trainers), but I'm reluctant because they wouldn't fit in her skates.
I couldn't believe the lack of offerings for her age/size.