My friend also received the same grades during 2013 AS exams, C in chemistry D in Physics and E in Maths, he spent one whole year studying for repeating his AS exams, and in the next year 2014, he got straight 4 As with a additional 4th subject English.
My advice to you is to talk to her and convince her that bad AS grades doesn't mean that it's the end of the world, she can always try again and succeed.