When Frida is brought home from hospital and lying in her bed in a cast, through days and nights, the amount of photos on her bed changes from 1 to 2 and back.
In the opening sequence, Frida is lying in her bed, which has been loaded onto a truck which is driving through Mexico City. She is staring directly upward at the mirror mounted on the underside of the canopy over her bed. In a close-up of her face, we can see her earrings dangling. But they are not dangling toward the ground, but rather toward her feet, indicating that she was upright for the closeup, not lying in bed.
In a scene taking place in 1933 Rivera mentions Happy Rockefeller, Nelson Rockefeller's wife. In reality, in 1933 Happy was only 7, and wasn't named "Rockefeller" yet. She and Nelson got married 30 years later, in 1963.