“It’s her photo ‘Migrant Mother, Nipoma, California, 1936’ that is her most famous.”
I humbly offer this tip for improving your writing: Get some sort of that trap — and kill your thats.
Look through your first draft for the word that, and if you find it, I lay 10-to-1 odds you can do without it.
Furthermore, if you find the phrase that is, you’ve almost certainly got a case of that fat.
Much simpler to say: “Her photo ‘Migrant Mother, Nipoma, California, 1936’ is her most famous.”
If every writer in history had eschewed that is from the beginning, the world would have way more ink left today.