Olivia and her three siblings bring a sack lunch to school each day, consisting of a bagel, an apple, a cookie, and a juice box. When Olivia's mom goes grocery shopping, she likes to purchase the same amount of each lunch item so that she can make complete lunches, with no leftover items. However, each item comes in a different sized package, as shown below:

Bagels: six in a bag
Apples: eight in a bag
Cookies: twelve in a box
Juice Boxes: nine in a box
Find the least number of packages she must purchase in order to have the same amount of each item. Then, complete each statement.

Olivia's mom should purchase how many boxes of cookies?