What specifically does she define "writing" to be? What exactly is she writing, and how much? What does her process look like?

One might also consider the idea of active reading and writing notes. I may not "write" daily in the way she means, but my note writing, is cumulative and beneficial in the ways she describes in her list. I might further posit that the amount of work/effort it takes me to do my writing is far more fruitful and productive than her writing.

When I say writing, I mean focused note taking (either excerpting, rephrasing, or original small ideas which can be stitched together later). I don't think this is her same definition.

I'm curious how her process of writing generates new ideas and creativity specifically?

One might analogize the idea of active reading with a pen in hand as a sort of Einsteinian space-time. Many view reading and writing as to separate and distinct practices. What if they're melded together the way Einstein reconceptualized the space time continuum? The writing advice provided by those who write about commonplace books, zettelkasten, and general note taking combines an active reading practice with a focused writing practice that moves one toward not only more output, but higher quality output without the deleterious effects seen in other methods.