Since Isabella saves 2 nickels today and doubles the number of nickels she saves each day, we can determine the number of days it will take her to save more than 500 nickels by continuously doubling the number of nickels saved each day until it exceeds 500.
Starting with 2 nickels, we can double the number each day:
Day 1: 2 nickels
Day 2: 2 x 2 = 4 nickels
Day 3: 4 x 2 = 8 nickels
Day 4: 8 x 2 = 16 nickels
Day 5: 16 x 2 = 32 nickels
Day 6: 32 x 2 = 64 nickels
Day 7: 64 x 2 = 128 nickels
Day 8: 128 x 2 = 256 nickels
Day 9: 256 x 2 = 512 nickels
It will take Isabella 9 days, including today, to save more than 500 nickels.
Therefore, Isabella will save more than 500 nickels in 9 days.