Renewing FLR(M) - basic query

First time post. Apologies if I am repeating a common question.

My wife needs to extend her marriage visa as her 2.5 year permit runs out in 2015.
She'll have been in the UK less than 5 years in total so I'm assuming we apply via FLR(M) in the same way as the initial marriage visa. However in the guidance notes it states:

"You may not need to provide evidence of meeting the English language requirement if you have previously done so as part of a successful application for leave as a partner or parent."

We have obviously met the requirement previously as part of a successful application but it's not clear whether my wife needs to take an English test again or not. In what circumstances would she need to take it again? The Home Office site just sends me in circles.

No.