Here's a writing prompt that you can use to start writing today. Instead of just a photo prompt, this one incorporates both a visual image and a phrase.
Study the picture and then begin writing using the phrase she was stronger than she thought. I've made the picture extra-large so you can see more detail. You can completely ignore the many items in the photo if you like and use only the words. The phrase is more important. The details in the picture might be of some further inspiration. The more you look at the picture, the more you see.
Give it a go and see what comes from your creative mind. Write a paragraph, a story, or a poem. Maybe even a personal essay. Your choice. I'd love to see the results but the comments section will only take a small word count.
Have fun with this one!