Medical Marijuana may be available, and work well - But insurance, as far as i know won't pay. Mu husband revd a couple sample capsules. It would cost 700.00 to get that kind of script filled. Though it may increase the appetite, you have to be able to eat.
I don't know how old your Gram is, but there are many variables. Most times it does take a month or so, maybe longer, to get back to not just wanting to eat, but being able to. This surgery is very traumatic to the body. They have re-arranged the digestive sytem. My husband did not have the surgery, we were told the tumor t the junction of the esophagus and stomach could not be resected. All I can offer is, try not to overwhlem her with questions of what she wants to eat. Just offer oatmeal, popsicles, italian ice, ice chips, mashed potatoe, applesauce, try no sugar for anything, but if she does not like it without sugar, give her what she wants. Try the liquids first. She has to basically re learn how to swallow things. Be a liitle patient with her. If you think something is really wrong, she may give signs that there is, if not ask the docs. If it goes too long, get a scan to see whats going on. Prayers and Hugs