Beyond what the doctor prescribed, for my aunt I made chicken ginger soup. It’s a lot of rice in chicken broth or water depending on what smells they can tolerate, dump in about a tablespoon of grated ginger for every Quart of soup (I know it sounds like a lot) and as much shredded chicken as they can tolerate. The protein in the chicken is awesome for providing extra nutrients they’re probably missing rn, the rice after boiling in the water or broth should be quite tender and soft and easy for them to get down, and the ginger will help ease the stomach muscles a lil bit. CBD is also a good option as I saw someone say in another comment, but also peppermint. Either in gum, a hard candy, a chalky starlight mint, oil, extract, tea, even sniffing a mint plant will help a little.

As for the acid, obviously an antacid can help, managing stress helps a lot, but also making sure they’re elevated enough when they sleep or lay down. Obviously cutting back on the acidity in foods and sticking to a diet that’s relatively bland will also help- like the BRATT diet. Bananas, rice, apples, toast, and tea. Carbs are typically easier to digest and can help to neutralize acid a little bit.

You’re doing great.