One of my student's is currently playing Beethoven's Rondo in A major for a Beethoven piano competition for young students (under 11 yrs), and I was wondering how much difference in tempo between the A major section, and the D major section would be permissable. Playing the triplets in thirds is quite difficult for this student, and we are obviously going to have to vary the tempo...but by how much?

? Any suggestions?
Wenat