[General] cover

[Maybo]

Peter made a mistake and his teacher scolded him, but his mother said it was not her son's fault and lied.

Can I say "Peter's mother tried to cover his son or Peter's mother try to cover his son's fault"?

 

[bhaisahab]

Say 'his mother said'.
Say 'her son's fault'.
Say 'tried' not 'try'.
Now rewrite your sentences.

 

[Maybo]

If you cover for somebody, you provide an excuse for them, Merely saying that it was not their fault is not covering for them. If she had, lying, said that she had caused him to make the mistake, she would have been covering for him.

Are there any other words to describe this situation if I don't use cover?