So This Is A Hard One To Decipher, My 4

So this is a hard one to decipher, my 4 year old daughter on Tuesday 31/5/16 morning went pale and vomited and had the day off Kindy, on Wednesday at Kindy they rang me in the afternoon and her temperature spiked upto 39 degrees and she was lethargic, she went to Kindy late Thursday because she seemed fine happy playing in the morning at home, Friday she napped in the afternoon and again lethargic then went pale again temperature spiked 38.6 that night (no vomiting), she was ok Saturday, Sunday (yesterday) in afternoon she went pale again and said she was sick then slept for a few hours, didn't check temp, my mum has her today and has said once again she has turnt pale and is asleep, unsure on temp as im at work. So this has gone on for nearly a week now, but very mild symptoms, only time she vomited was Tuesday, shes not herself, what could this be and how do i tell a doctor a visually fine looking child is having these waves of sickness.