Define "lady" how you wish. For me, a lady radiates strength, self-assurance, wisdom. In that light, I interpret the lyrics as an acknowledgement that external circumstances don't define the woman, the woman defines her circumstances. The world can crumble around her, and she's still a rock thanks to her character and innate value.

ETA: As someone who shares your overarching view, it might be worth a conversation with the school. How is the school interpreting the lyrics?

What is to give light must endure burning.