Mark, don't mess with success. The wine is fermenting, and that's the
important thing (much better than a stuck fermentation, I assure you).
But, if you don't want a wine that dry (and it is getting DRY), then
you'll have to sweeten it back anyway, so you might as well wait it
out and be safe.

For the record, I never expect a wine to finish fermentation in
secondary in only 10 days (by the way, "secondary fermentation" is the
second inoculation with yeast in making sparkling wine; the
fermentation in the secondary is still part of the primary
fermentation). I expect it to ferment for 30 days, and if it finishes
before then I am mildly surprised. If it takes longer, so what? This
isn't a foot race. But then, you are talking kits and I am talking
grapes or fruit....

Jack Keller, The Winemaking Home Page
http://winemaking.jackkeller.net