HOW lONG.........wHEN IS IT GONE FOR GOOD?

My friend has a yeast infection..ewww lolz nah an she asked me when do she know it over with or should i say when is the yeast infection gone for good..she said she been using sum kind of cream stuff and that it really stops the burning and itching..She said she started using it friday of last week an she got the yeast infection tuesday of last week..SHE REALLY NEEDS HELP..