My old cat used to eat only what she needed throughout the day. Only dry food.

My new kitties are trash cans. Everything eatable goes in. I feed them twice a day, dry food, only the recommended amount as stated on the food package and as recommended by the vet.

The vet said it's easier to keep them at a decent weight then to have to put them on a diet.

When your cat eats whenever she wants food, I think you should be fine with feeding her once a day. But make sure you only feed her enough for her weight and age. The website of the food brand should list a recommended amount, otherwise ask your vet.

When she's an adult (1 year and older or 6 months and older when castrated) it's recommended to feed her adult food, only dry food, it's better for their teeth.

Never feed your cat milk, cats are lactose intolerant.

When she throws up on a daily basis, go to a vet. This isn't normal, she might be ill. Make sure you have cat grass for her, they need grass to help throw up, when they have a hairball for instance. Always make sure she has fresh water access.

Make sure your cat won't become obese. Animal obesity is animal abuse. Next to them having a terrible life, they will get sick much faster and their life much shorter, which is not only sad, also expensive.