Great questions from
@Tycine1 and answering them can give us plenty of clues.
In addition to those, can you recall where she was hanging out right before you noticed her distress? Do you have any standing puddles with scummy water? How about compost that may be deep and putrid at the bottom where she could have been digging things up?
How about pesticides and machinery in the area that may be leaking fluids onto the soil? Could she have encountered anything moldy? Table scraps? A discarded apple or peach that was moldy?