So... there are a number of dimensions to this choice. Sure, there's a degree of technical skill here, and there's the effect it'll have on us, but there's also the effect it has on Punk Rock Girl herself. This isn't just a song. It's the fundamental argument we'll be making. She is *highly likely* to be making an argument about rage and frustration and the fundamental unfairness of the world, when those in power oppress you, even unintentionally. (...and without caring. Hi, Cai Shenhua!) So, how do we counter that? What can we say in the face of that that she might find at all compelling?
Well, there's Mom. From her perspective, and that of the girls she'll be bringing with, CRX is the power that reached down and protected them. It feeds more into the story of what Renxiang is *trying* to be, in contrast to the story of what Shenhua *is*. You can even come around the other side and get some of that same thing from Bai Meizhen, who was able to thrive in the sect because CRX put what was right before immediate politics. We can weave in our gloomy girl tendencies a bit by including the darkness that comes before that light, or that sinks in in its absence.
This does a bunch of things. It's an argument that might resonate with our opponent. That has potential social implications later on. Also, this sort of battle can absolutely be won or lost on the strength of your ability to convince your opponent of the strength of your argument. It does good things for our liege. It's straight-up propaganda in her favor, but it's exactly the right sort of propaganda to be reaffirming to her personally - an argument that boils down to "yeah, but she isn't going to be her mother. She's going to be better than that." is really strong with respect to her personal issues. Finally, to me at least, it seems like the sort of thing that might help us personally break through our drek (as much as anything is.) It starts in the bad places, and pushes through to something more inspiring.
To me, Mom and family are by far the best place to go for that particular inspiration. It's all about them, really.
[X] She could use a more human perspective. Even if her friends and family were not musically talented, they could give her feedback and advice.