My cat spitting up????

Alexandria • ~👶Rainbow baby 10/21👶~ - Happily married 💑💕 3/29/15

My kitten is 3 months and she has done it three times. she meows and then she throws up or spits up? It was first white stuff like saliva and then some of her cat food. Should I change her kitten food? its kitty Meow mix. When her bowl gets empty I give her a little more like 3 or 4 times maybe. Am I doing anything wrong. ??