It's old news now, but I never got around to blogging it:
It was easier to potty-train the cat, frankly. I mean, show kitty where the litterbox is, and done. No worries. Not so with the humans.
But anyhow, before Clare and Brent left for TX, I decided to just unilaterally usher in the grand new era of big-girl pottying. Took Clare shopping, bought a dozen or so panties (in our house, "pannies," and Clare will correct you) of Clare's choice (Elmo, Dora and Little Mermaid) and put her in them and just dealt with the, uh, fallout.
About three days later and several pee-puddles and poopy pants later, she was as reliable as I am, and went off to Texas where other people reinforced the new regime on my behalf for three weeks.