Complex sentence: She received two commissions from the Mexican government in the early 1940s, but never completed the first one, possibly due to her dislike of the subject, and another commission was rejected by the commissioning body.
Split into simpler sentences: She received two commissions from the Mexican government in the early 1940s. She did not complete the first one, possibly due to her dislike of the subject, and the second commission was rejected by the commissioning body.