Pigs sneeze every now and then just like us. If you start to notice multiple sneezes within a short time frame then you need to get her to the vet.
I would also suggest to spray perfume is another room, it can bother their noses! I konw it makes me sneeze
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It sounds like you have a pretty good idea of her normal personality. If you notice any changes in her normal behaviour, that could be a cause for concern as well.