I wouldn't worry too much about 'repeating.' If she were close to middle-school aged, you might have some issues, but as others have said, at her age, given the broad range of abilities and subjects that are covered in primary schools, even if she is ahead of her classmates on certain topics, there will be other things she's probably never been exposed to. I imagine it will all even out. If nothing else, an 'easy year' will give her time to get used to the culture shock of the move itself, plus the big differences in school culture.