Emily earned $166 more in her account than Katie.
We use the compound interest formula for both of these:

For Katie's deposit:

This gives Katie 6083.26-5000 = 1083.26 in interest (1083, to the nearest dollar).
For Emily's deposit:

This means she earned 11248.64-10000=1248.64 in interest (1249, to the nearest dollar).
The difference in interest is given by 1249-1083=166