If she can use a slow cooker in her accommodation, a very simple beef casserole could be cooking while she is out, ready to eat when she gets home.
Ingredients are a pack of cubed beef, an oxo cube, a level tablespoon of flour and some hot water.
While the kettle boils, put the flour into a plastic bag, add the Oxo ( fold back the corners of the foil on the Oxo, press the back of a teaspoon onto it to break it up without breaking the foil, then tear the foil and pour the crumbled contents in with the flour) close the bag and shake it around a bit to mix. Open the pack of meat, add it to the flour, close the top again and shake and squidge it around to coat the meat with the flour mixture.
Pour it all into the slow cooker and add enough water to almost cover the meat. Stir well, and wipe the sides of the slow cooker with a bit of kitchen roll if they have got messy.
Cover, switch on to "auto" if it has that setting (It will heat at high for the first hour, then low for the rest of the time) If not, cook it on low. Cook for at least 4 hours, and it is better after six.
Serve it with frozen mash and tinned carrots, and mop up any excess gravy with bread. (for best value, buy a big bag of Auntie Bessie's or supermarket own brand and just use as much as you need each time. She could even eat just mash for an instant snack in 2-3 minutes, with grated cheese and some chutney or a sliced tomato)
Variations - use cubed chicken and chicken Oxo instead of beef, pasta or rice instead of potato, add some Auntie Bessie frozen dumplings to the slow cooker half an hour before it is ready..