Why Is My Kitten Throwing Up White Foam?

My kitten throws up white foam. Does this mean she has a food allergy? I’m not sure what it is that causes her to throw up and then diarrhea, but we can’t figure out what the problem is. Please help us!

Possible Causes of White Foam Vomiting in Cats: Food Sensitivity? Cat Scatology – My Feline Support Group