Shockwave rules are on page 31 of the rulebook, but to give a quick rundown:
Meredith first needs to pass the simple duel to see if the action succeeds. If it does, she places a 30mm marker anywhere within range and LoS. Then, since it is a Shockwave 2, you measure out 2 inches from the marker. Every model that is within the circle made will need to take the MV 13 simple duel, and if they fail will suffer the effects, which is the 2 damage and Poison +1.