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If you wormed her at home, you might not have gotten the problem taken care of. There are MANY different types of worms and each over the counter wormer that you can buy treats a different one.
I would suggest that you take a fecal sample to your vet and have them take a look and let you know what you are dealing with. If they find parasites, they can give you an appropriate wormer. Most vets won't charge for an office visit for this.
Also, if you have not had her tested for FIV/FelV, you will want to do so as soon as you can. Cats with disease are often not as healthy as others and you want to be aware of potential problems.
Since she is vomiting often, she might have reflux disease. If this is the case, your vet can prescribe an antacid like tagamet to help.
Let me know if you still have questions.