For example, she loves Edgar Allen Poe, but the vocabulary makes it a little difficult to understand without diving into a dictionary every other minute ("The Cask of Amontillado"). Something like "Hills Like White Elephants" by Ernest Hemingway is a little better, as it's just a few pages long, is written with very basic descriptions and dialogue, but it still has a deeper meaning and cultural importance. Any short story suggestions you can give though, high or low register, well-known or unknown, are more than welcome and very appreciated.
Personally, I recommend "Lamb to the Slaughter" by Roald Dahl. As well as "La Parure" (The Necklace) and "Allouma" by Guy de Maupassant (especially if you're trying to learn French). Thanks in advance!