There are several information's of immense importance already given in the question. based on those information's the answer can be easily deduced.
In 1 hour the distance walked by Ebony = 3 1/2 miles
= 7/2 miles
Then
In 1 1/3 hours or 4/3 hours,
the distance walked by Ebony = (7/2) * (4/3) miles
= 14/3 miles
= 4 2/3 miles