AI was making MMF earlier today and ran out of powdered sugar while it was still sticky. I should've known better as it's a very rainy and humid Texas day. I want to salvage it as I hate wasting things! I covered it in Crisco and wrapped in in plastic wrap. Will it be ok if I add more powdered sugar to it later this evening, after I get a chance to go to the store? Or do I need to scrap it and start over? Any help is much appreciated!!!

It will be fine!  I was in the exact same situation last weekend.  When I was ready to work with it and had the sugar, I took a handful of fondant and kneaded in the powdered sugar a little bit at a time.  Dust plenty sugar on your work surface and keep your hands lubed with shortening, then the stickiness should be reduced.  Hi, from Austin!  Our rain just dried up!

AThank you so much!! I figured it would be, but I wanted a second opinion.

If you have trouble working in the sugar, just heat the fondant a bit in the microwave and it will be easier to work with.

AThank you so much. Glad it will be ok! Turns out I won't be able to add more powdered sugar until tomorrow! Crazy schedule with Valentine's Day and all! Happy caking to all!