"Self Portrait with Monkey" is one of the many paintings she created of herself. As you can see here, she was not ashamed of having uncommon traits for women at the time. She never hesitated to depict herself exactly as she was, which is a heroic trait.
Frida Kahlo was never known to be "like other girls". She was very unique, and she embraced it. Thus, seeing in her artwork, she drew unique designs that reflected on her own personality.