Emperors Valentinian I, Gratian, and Valens issue a new law exempting "low born" women from working in theaters if they convert to Christianity.
According to this new law:
"If a woman from the lower class is obligated to perform in spectacles and tries to avoid the compulsory duties of the stage, she is to be assigned to theatrical services — but only if she has not found the most holy religion and reverence of the Christian law which bind her to that faith.
We forbid women to be dragged back to the theater if a better way of living has released them from the bonds of their natural condition.
We also command that such women be free from any prejudice that is derived from the stage once they have an exemption from the compulsory public service of an indecent character..." [CTh 15.7.4]
Performing on stage is not viewed very positively and is not good for a person's reputation. In Rome, performing on stage is akin to prostitution: it might not involve sex, but it's selling one's body to the public for entertainment purposes. Thus working in the theater places a person in the lowest social classes.
Anne Duncan writes in her book Performance and Identity in the Classical World:
"The Romans made persistent connections between prostitutes and actors in law, in literature, and in clothing conventions. These connections suggest an association in the Roman cultural imagination between sexuality, public life, and performance.
Essentially, both prostitutes and actors were thought to be people who "faked it" for a living. ...The stigmatization of both groups by the upper classes as "low-Other" worked to constitute both prostitutes and actors as objects of desire.
... Catharine Edwards has discussed the ways in which the Romans viewed actors, prostitutes, and gladiators as low, shameful, yet desirable performers; she argues that the Romans associated public performance of any kind with immorality, especially if women were involved.
Her findings are supported by Dorothea French's study of the status of mime-actresses in the Christian era of the Roman Empire. Both articles make the case for a Roman tendency to view women who "performed" in public as whores, both figuratively and insistently literally."
If one is pagan or Jewish there's no way to avoid any of this, but if one converts to Christianity, all sorts of privileges will be made available.