That could be tough to hear over the storm.
The rules on Magical Senses (pp. 113-114) mention the need to penetrate, but I assume that applies only if the sense is the medium for detecting something within the person of a creature with Magic Resistance--it shouldn't apply to species emitted by that creature. (The creature is magical, but I'm not sure the species emitted are themselves magical--and that seems to be the consensus: Imaginem and Resistance)
So, an InIm spell to enhance hearing is base 1, +3 for target Vision, +2 for duration Sun, and let's give it a +1 for complexity, in that we only want to make it easier to hear crying (not, say, the storm). That's a level 15. Viola's casting total (with Potent Spontaneous Magic) is In 8 * 2 + Im 8 +2 Sta + Aura 6 = 32 + a stress die, all divided by 2. She couldn't quite manage it without Fatigue, due to the need to double one Art and/or add the stress die..
Die roll: 8, with a Weird Magic roll of 5.
How's the storm coming? We don't want to proceed until it's started to get dark. The need to rest for a couple of minutes to recover the Fatigue provides a convenient excuse to delay a little longer.
Scott