If Baz Lubrmann were producing a film version of Julius Caesar, then there could be a part for Servilia Caepionis that would well serve his style. However, since the historical facts about the mother of Brutus are somewhat uncertain and variable, they may have not been appropriate to the design of Shakespeare's work, a drama that has as its focus the tragic character of Brutus. For one thing, Servilia reportedly was not fond of Portia, the wife of Brutus, so there could have been additional conflicts there which would distract from Portia's devotion to Brutus. Besides, her influence upon Caesar as his lover and as mother to Brutus are not entirely relevant to the text of Julius Caesar.
For, the focus of Julius Caesar by William Shakespeare is upon the inner workings of both Caesar himself as a ruler who has overreached his power and Brutus, whose misjudgments lead to his failure in war and tragic end. Thus, thematic to Shakespeare's play are the words of Cassius to Brutus in Act I
Men at some time are masters of their fates.The fault, dear Brutus, is not in our starsBut in ourselves, that we are underlings. (1.2.141-143)