First, let me give you two examples:
She has a difficult job. She must work hard.
She has a very difficult life. She must be patient.
Since "must" can also be used for meaning "most likely" instead of its first meaning. Doesn't it cause ambiguity in these kinds of sentences? If I am meaning she most likely works hard or that she is most likely patient, can't it be understood as like she should work hard or she should be patient (I know that "must" is stronger than "should" by the way)?