I have a 7 year old cat she vomits all the time and it's not a hairball she's been doing it for a while what could be wrong?

She could be diabetic. Does she drink a lot of water and pee a lot? Please take her to the vet for a diagnosis.

Here's an article that may help you.:

vWhat Causes Cat Vomiting

My mother's cat vomits if she has too much to eat. Abby (the cat) is a gorger and will eat all the food in her dish. Mom found that when she gave her too much food, Abby would vomit.

Today, Mom feeds her a small portion in the morning and another small portion at night. That has seemed to stop the vomitting.

Another cause of vomiting can be nervousness. I know that when I get ready to go on a trip or there is a change in my behaviours, my cat gets nervous and starts to vomit. He is quite the little baby! Have there been any major changes in your household lately? Big trip? New baby? New carpet/furniture?