This is a great approach! I've been using it, though I haven't posted here yet. Right now, my main project is revisions on book 2 of my current series, but I'm also working on the first draft of the next series. By the time I finish my daily quota of revision, I'm pretty wiped out (CFS/ME severely limits my mental and physical energy) but 50 words in the evening, that's easy! I focus more on writing scenes/parts of scenes than word count, and always end up with way more than 50 words. 800+ tonight.
PS: Lorri, I'm so sorry about your kitty. I've lost kitties myself (though none to illness), and they each leave a kitty-shaped hole in your heart.