Could she have thrush?

Izzy is 15 days old and has a white tongue.  I can remember Emy having thrush at about this age but she had white patches over her cheeks.  Izzy just has a white tongue at the back of her mouth.  She is still feeding well (bf with formula top ups) but has been a little fussier last night and today.  The white tongue just looks like a coating of milk.  Is there anything I can do to check if it is just risidual milk or thrush.  If it is still there tomorrow I will make a dr's appointment.

If you scrape it with a spoon, if it's milk residue it will come off. If you can get a spoon in your baby's mouth that is - I always failed

Will try.  Thanks Hazel.