Talking about slow shrinking which takes several hours or days, I'm not a big fan of it.
Probably because there are so little stories do did it well.
However, in this one it makes perfectly sense, which is also explained reasonably with the natural decay time for molecules.
I like it if knowledge or science is embedded in stories, it makes it feel more real.
And the most important fact, things happen while she is shrinking.
It's not like she is watching her clothes growing. An every inch lost has a real impact on her world and the people around her.
And for me it was fun waiting until she got my favorite size.
