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.
Early in her New York trip Frida is watching 1933's King Kong. Later she is called home to tend to her dying mother. Several scenes later we see her at her mother's grave and it shows that she died in 1932, a year before King Kong was released.
In the movie when Frida loses the baby it is after Diego had painted the Detroit mural, and they are already in New York. But, in fact Frida lost the baby when Diego just started painting the Detroit mural in 1932. She lost the baby at Henry Ford Hospital in Detroit. Also, there is a scene that shows her painting "Henry Ford Hospital" and shows the finished painting without the words on the frame of the bed.
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.