She wants all this to be resolvable neatly and safely and not be traced back to her. She wants to not lose her housing or her liberty, not disappoint Sakura-san, and fix Kamoshida without anyone getting seriously hurt in the process.
There's really two routes here: gather evidence of abuse and bring it to an adult with leverage, or get together infiltration supplies and try to brave Kamoshida's palace.
In the first case, what are the risks?
One: Her housing and her liberty, because she had better pick that adult damn carefully for it to not be seen as her just repeating her previous "assault." If word gets back to Sakura-san or the police she could be out on the street or back in prison.
Two: Disappointing Sakura-san, because she can't keep her head down.
Three: Alerting Kamoshida with her evidence-gathering, which could make the abuse far worse.
Four: Failing to fix Kamoshida due to insufficient evidence of abuse or insufficient reputational weight. He's probably being protected by the principal of the school since the principal is also a scumbag. In which case Kamoshida probably gets ten times worse because he knows he's invulnerable to scandal.
In the second case, what are the risks?
One: Her housing and her liberty, because if she possesses even a fake gun that's definitely violating the terms of her probation.
Two: Disappointing Sakura-san, because she'll look like a delinquent for possessing sketchy replica weapons.
Three: Dying to the shadows in Kamoshida's castle, in which case she and the people she brings with her are probably lobotomized.
Four: Failing to fix Kamoshida due to dying in his castle, in which case he goes on unimpeded as he has been and everyone in this conversation is also braindead.
Neither is an attractive option. She's not important; if she dies in Kamoshida's castle or gets thrown in prison again that's fine. But taking Morgana, Ryuji and Ann to their deaths with her would be unconscionable. Similarly, if she fucks this up and Kamoshida seriously hurts someone, or becomes invincible to scandal due to an unsubstantiated accusation, that's on her head too.
This decision feels heavy as hell. Third options, third options...
"There are two basic plans we could try," she says at length. "We could do it the mundane way. Gather evidence, find a trustworthy adult or a couple trustworthy adults who'll speak for us, try our best to support the victims. Or we could do it the magical way. Get fake guns, medicine, granola bars, whatever else useful we can think of. Get together and delve into the palace and steal the thing that's causing the distortion."
She looks at Ryuji and Ann. "I want, more than anything, for everybody to get to be safe, but this isn't going to work out that way. Whatever we do comes with serious risks. If we approach the victims we could attract abuse to them; if we fight in the palace we could literally die. But I think we've just got to throw everything we've got at this problem. Talk to the victims, get fake weapons, try to find the treasure that Kamoshida's hiding in that castle, just work the problem from both ends and whichever one seems more likely to work go with that one. The important thing is that Kamoshida gets kicked out of the school; how we do that is less important to me."