harry potter - How come Hermione tried spells before boarding the Hogwarts Express?

OK, so here is a sequence of facts:

• 
  

  It's prohibited to use magic in Muggle areas.

  
  
  


• 
  

  Before boarding Hogwarts Express, Hermione lived in a Muggle area.

  
  


• 
  

  (this one I'm less sure about) Hermione and her parents must have been told, upon getting a wand, about restrictions on use of magic. Or she would have read about it in Hogwarts: A History or some other book.

  
  


• 
  

  If so, this being Hermione, she would never have violated the rules.

  
  



• 
  

  Yet, Hermione told Ron in the beginning of PS, on the train, that she already successfully tried out some spells after witnessing him trying to turn the rat yellow. This was right after they boarded Hogwarts Express, so she must have done it before.

  
  

So, how could she have possibly practiced any magic?

I'd strongly prefer canon or JKR based answer if available.

Answer

Based on the following quotes I suggest Hermione had time to practice these spells on the train.

"I just take the train from platform nine and three-quarters at eleven o'clock." (PS chapter 6 e-Book page 65)

Then

Around half past twelve there was a great clattering outside in the corridor and a smiling, dimpled woman slid back their door and said "Anything off the cart, dears?" (PS chapter 6 e-Book page 73)

After the chocolate frogs, many as Harry had a few cards, Neville arrives in the compartment

There was a knock on the door of their compartment and the round-faced boy Harry had passed on platform nine and three-quarters came in. (PS chapter 6 e-Book page 74)

Finally,

He had just raised his wand when the compartment door slid open again. The toadless boy was back, but this time he had a girl with him. (PS chapter 6 e-Book page 76)

The spell fails, she mentions her simple spells all worked for her etc. She also says

"You two had better change, you know, I expect we'll be there soon." (PS chapter 6 e-Book page 77)

before leaving their compartment. Regardless of right or not this means a considerable amount should have passed.

This leads me to believe she may have tried some spells on the train, having memorized the incantations at home when she learned the books off by heart.