Hello Clark, It seems your wife has been having episodes of weakness since past few days. Its difficult to attribute everything to a single cause. She might have been overactive leading to episode of less activeness. Also you need to look into the nutritional aspect as she has been involved in water exercises. The surgery planned could be taking a toll on her mind and she must be in a stressful period. Positive support from your side could be helpful in improving the symptoms. Anemia could be a cause. Check for hemoglobin to rule out anemia cause. Hope your query got resolved. If you have any further queries, happy to help.