Hello and thank you for your question.
Tulip ingestion in cats generally results in possible contact irritation and gastrointestinal irritation... meaning vomiting, anorexia, and diarrhea can occur. Generally, it is not toxic to the kidneys or liver, which is good news. However, if anorexia and vomiting continue for days, they can easily get dehydrated which will just worsen the symptoms. Also, if she is an overweight/fat cat and suddenly becomes anorectic, she is at risk for developing a type of liver failure that can be deadly if her appetite is not restored quickly. Also, there have been some reports of ingesting tulip bulbs causing nervous system disorders, so there definitely is some concern.
It does concern me that this has been going on for a few days now... You could try some pepcid AC (famotidine is the generic name)- the dose would be 2.5mg/cat every 12 hours. Otherwise, there really aren't any safe over the counter medications for cats. If this continues, I would seek veterinary care. Even if you can't afford expensive testing, they may be able to give some fluids or injections that will help speed her recovery.
I hope this helps and best of luck. Please let me know if you have any additional questions.
I also just wanted to make sure you meant tulips, and not LILIES. Lilies are extremely toxic to cats and ingesting any portion of the plant can cause a life-threatening kidney failure even with aggressive immediate treatment. If there's any chance what she ingested was lily plant, seek veterinary care immediately!