@@Darkaine
If you are worried about dehydration I can recommend pedialyte. It comes in different forms - powder to dissolve in Water, freezer pops or ready to drink in a bottle. It quickly replenishes liquids and electrolytes. I also used "Smartwater" in my first couple of weeks after surgery.
I was in a similar situation as your wife and had a hard time to get my liquids in. One 'trick' that helped me was using 1 oz cups , fill 4 for each hour. I tried to finish one cup every 15 min. Honestly it was hard in the beginning but it helped me to advance.
Hope that helps :-)