I have already stated that Melisandre saying it was the only way was her justification for the action. The same as "I didn't have a choice" and Davos was simply taking away her justification that it did not produce the desired result anyway. The religious reasoning doesn't work for you since you are the one claiming she was certain of a win so therefore she could not have sacrificed Shireen for this reason. Well obviously again if she can be tested she had doubts about the certainty. It was GRRM who stated the extended winters and summers is due to magic, not me. He did not include strange weather patterns such as extended blizzards, that is entirely your story, built on what you think is in my mind. She did not say show us the way. You are doing it again putting words into the characters mouths to suit your reasoning. She said help us forward towards the light. This means bring about the events to enable them to fight the darkness coming. Melisandre thinks Stannis needs to be king before he can fight the darkness. I can quote where she states this. She did not ask to clear the storm, she didn't care if it was there or not, she wanted to have the battle and Stannis become king. I can quote where she states this as well. So far you have not offered any real support for your claims except "well it was implied, even if it wasn't stated" "well confidence = has magic that works".