on my mini I close app all the time with 5 fingers
she didnt say what iPad she has, if it is older than I guess she can't but if it is a newer one she can
Just to avoid misunderstandings: you performed the five finger swipe to show the multitask bar, and then swiped the thumbnails upwards with four/five fingers, like this:
I just tried it with my iPad Air, and also on my iPad mini. I can use two or three fingers to slide them upwards, but it's not working with four.
Force closing apps this way works on all iPads with iOS 7 installed.