but she also was capable of writing "I am my father's daughter, I can face anything" early in the 7 Years War, i.e. retrospectively classifying those years of abuse as something she's currently drawing strength from in her miserable state.

Huh. I don't have context (are these in the memoirs? I stopped reading before that point) but is it possible that she's talking about FW's character (I mean, he seems to have been at least as stubborn as Fritz!) rather than the abuse in particular?

...but yeah, that all makes sense. (And Wilhelmine does seem like the most self-aware and peacemaking of them, in general.)