Does she have a really good basic cookbook? Back in the day, that would always be Joy of Cooking,

Maybe some quality canned soups for nights she doesn't feel like cooking?

If she's not a cook, condiments like ketchup, mustard, mayo. Powdered or canned milk or milk substitutes if she is unlikely to go to the market often. Beef and Chicken stock or bouillon can dress up rice and pasta if there isn't any meat available. Self rising flour to make biscuits, dumplings, pancakes etc. - even simple cake desserts. Honey and syrup.

Joy of Cooking may not be right -- "too much information" - how about "Cooking for Two" (or "..One"), or "Tasty Ultimate", or "5 Ingredient One Pot Cooking" (my DD's favorite).

For spices you can make it easy for her with Italian Blend, Old Bay or Seafood Blend, and add garlic powder, onion powder, red pepper flakes, and paprika to your list.

Instead of self-rising flour I'd recommend a big box of Bisquick.

Canned tuna and/or salmon, cans of diced tomatoes, corn, green beans, baked beans, and even spaghetti-o's for fun.

What does she have in cooking equipment? Hot mitts, pans and skillets, cookie sheets, pyrex baking dishes. Most of these pots and pans should be smaller sizes for her and a friend, though a bigger pot for cooking pasta.

Crackers? A few sauces for cooking, like barbecue, salad dressings, etc.? Tortilla chips?

Canned spaghetti sauce, cereal.

It must be obvious that I'm an old person, just to suggest a cookbook. Most/all younger people just use the internet. But there is nothing better for inspiration than just browsing a book. And one book that you trust instead of putting ingredients into Google and getting all sorts of garbagy recipes.

sushi, I think a cookbook is a great idea.

I was thinking, as a previous poster mentioned, of something more simple in terms of a cookbook, like Cooking for beginners/10-minute meals, 5 ingredient meals, etc. There are tons of them. The Joy of Cooking could be quite intimidating to a beginner (or even an experienced cook).

or the OP/aunt could make up some recipe cards of her favorite easy meals.

Congratulations for getting it right! That does sound like a perfect amount of "something". She has a job, and can buy things she wants to cook, but having to start from the salt and onions up could be daunting.

My daughter went through a rough patch and we guided her to the social security office who directed her to our state's food stamp program and then on to several food banks. We have several universities and therefore "starving students" who all line up without embarrassment with their peers to accept what we pay for in our taxes. Couch your words for this kind of support by saying that there are lots of people who care, all unknown, and all who have been there before, and this is only temporary. Even if she has a job, state services can give a little extra boost to her if she will only ask for it.

Baking powder, and a jar of Better than Boullion...maybe 2 jars one chicken and another beef.
And I would add some jarred chopped garlic and pre-grated parmesan cheese. A bit of cooked pasta, some of that chopped garlic, olive oil and pre-grated parmesan cheese and she has a "gourmet dinner"....and we will deal with the glories of parmesan reggiano and fresh sliced garlic at another time.
Oh and some bisquick!!

I was going to suggest coffee, tea or hot chocolate, and jarred pasta sauce, but you covered those already. the other things people often overlook that are actually kind of expensive are laundry and cleaning supplies.

I also like cookbooks, although I certainly can do an online search. Sometimes I just want to sit in my favorite chair with a book in my hands, and a lot of the time, it's a cookbook. I think it would make a great Christmas gift.

Good luck to your niece, I'm sure she's excited having a job and her own place. The excitement wears off when you realize that you are entirely responsible for yourself, including washing dishes and doing laundry, LOL.

As an afterthought, and given the bisquick recommendations, I do make many of my own mixes, including pancake mix, brownie mix, biscuit mix, and The Princess loves to make those "mug cakes" that make one cup and go in the microwave. She doesn't use a boxed mix, she makes her own, so that's a possibility too.

Annie

Each time my kids moved out (yes, a couple times each) I gave them a box of minute rice and some cans of chunky soup to fall back on.

I also make full recipes and freeze meals for 1 or 2.

This is for back up while learning to cook! It can be overwhelming to start cooking from scratch right off the bat!

Cooking Light has many 1/2 hr or less fairly healthy recipes. Rachel Ray has the 30 min. recipes, but they aren't, in my opinion all that healthy (tons of carbs and cheese, though I love that stuff, I try to avoid it as much as possible and why not start cooking with that in mind?)

I gave my non-cooking daughter a small George Foreman grill and she did learn how to cook chicken perfectly, then veges came later.

Offer to come cook with her if possible! It'll be fun, and make your relationship closer, while learning some new skills!

I don't think anyone has mentioned canned beans, so much handier for a non cook than dried beans. And can always be added to a meal at the last minute.

I'm a lurker but wanted to jump in and suggest frozen fruit and veggies. Our growing season has come to an end and I'm always reminded this time of year that frozen fruit especially comes in handy when fresh isn't always available. They'll keep a long time for a single person.