Divide the 5 yards by 3/4 yards for each one:
5 / 3/4 = 5 * 4/3 = 20/3 = 6 2/3 bracelets.
She is only using the jute for 18 bracelets.
Assuming she can't use a partial piece she needs enough jute to make 12 more bracelets.
Multiply the amount per jute needed by the quantity needed to make:
12 x 3/4 = 36/4 = 9
She will need 9 more yards.