So Hermione is muggle born, that means her parents and her definitely didn't know anything about magic before. Sooo how could she manage to enter Leaky Cauldron or Diagon Alley?
Because there is a secret passage to enter DA right? The wall that Hagrid tapped with his umbrella.
And also is it normal seeing muggle in Diagon Alley?
We saw Granger in Flourish and Booth