My understanding is that you just need enough to keep the bottom of the meat from scorching. With that much liquid, you'll end up poaching the pork rather than steaming it. Still good, just different.
For something really exciting (though it takes some time), cut garlic cloves into thin slices, then cut deep cuts, about one inch long, all over the loin. Then shove a slice of garlic into each cut, as deep as you can fit it. This turns out amazing!!!
Are you seeing the Wiggles live, Jen? My cousin's daughter brought her Wiggles DVDs with her when she came to visit. They are very silly but a lot of fun, too! Bet your twinzels will have a blast!