Mildred does not read for several reasons:
1. She is a cooperative member of society. Reading books is against the law. She is not about to disobey.
2. She prefers the parlor walls to other forms of entertainment. She likes the family because they do funny things. Ironically, the family actually does nothing. We see a report of their conversations and as readers we see how hollow and shallow they actually are.
3. She does not want to think anyway. When Guy begins to read to her, it confuses her. She does not understand feeling or thought and how they influence and support and build humanity.