Lung Function Tests

Hi posted a couple of weeks ago as daughter quite ill - well she is ill again not even 3 weeks gap and back on pred, this time trying a longer dose to see if that makes any difference. Doc was helpful and nice and for the first time ever wants a follow up appt to check she is responding ok to the pred! I just wanted to ask ... and I know specific medical advice can't be given... but just generally in peoples experience.... the doc said that the lung function tests will poss need to be delayed as they can't be done for 6 to 8 weeks after an exacerbation of asthma. Does anyone know if thats about right??? can't see us getting it done till next summer if it is!

Thanks again for everyones replies and advice last time - always makes a difference to ""sound off"" to people who know what you're on about!!