Why use "will" instead of "would" in this case

My teacher of Grammar at university told us that when we report a speech that was said in the past, we replace "will" by "would". However, in this example, she used "will" in the reported speech as well.
Here is the example:
"He won’t come on time," she said.
–> She didn’t think he will come on time.
Can someone explain please?