Frida Kahlo had an interesting, political and culturally important life, which means that it's great for the non-fiction bestsellers shelf. Many non fiction books are illustrated with Frida's portraits and paintings. Some books include other Latin Artists, since Kahlo's been such a huge influence over the last one hundred years.
More than a few books about Kahlo can be found on eBay or Amazon, including The Diary of Frida Kahlo by Kahlo herself and edited by Carlos Fuentes, Sarah M. Lowe and Phyllis Freeman, illustrated. A great more objective biography is the critically renown Frida by Hayden Herrera. There are also a number of children's and young adult books out there.