If she isn't showing other symptoms such as runny eyes, yellowish mucous, lack of appetite, dehydration I would hold off for a day or two. If she pretty much seems her normal self but with a bit of sneezing she might be having a slight allergic reaction to something. Could be the litter. Is this a new brand for you? Or did you just add litter to the box? I always keep some chlor trimaton in the cabinet. The four hour tablets. If they seem allergic to something, meaning they are sneezing but the mucous is real clear and watery then I will give them a half a tablet every 12 hours for a day or two and see if that clears things up.

Denyce