How did Elizabeth know the name was “John”

Question

The angel of the Lord only spoke to Zechariah about the name of the child to be born. How did she know about the name? Did the Lord reveal this to her or her husband told her? How she know what the baby should be named?

Luke 1

59 On the eighth day they came to circumcise the child, and they were going to name him after his father Zechariah,
60 but his mother spoke up and said, “No! He is to be called John.”

61 They said to her, “There is no one among your relatives who has that name.”

62 Then they made signs to his father, to find out what he would like to name the child. 63 He asked for a writing tablet, and to everyone’s astonishment he wrote, “His name is John.”

Answer 1

Then they made signs to his father, to find out what he would like to name the child. He asked for a writing tablet, and to everyone's astonishment he wrote, "His name is John."

He had all the time prior to this to write it out to her. That is most likely how he would have communicated it to her. Zechariah writing here is just to show everyone else.

Answer 2

The text doesn't say directly, so there is no certain answer. It's likely that Zechariah communicated the name in some other fashion.