To solve this problem you must apply the proccedure shown below:
1. You have that she walks 1/9 of a mile in 1/54 of an hour, Therefore, to calculate the time that will take her to walk 9 miles, you need to multiply 9 miles by 1/54 and divide the result by 1/9.
2. Let's say that
is the time:

Therefore, the answer is: 3/2 of an hour.