Hello, Lauren and welcome.
My name is ***** ***** I will be glad to help with your question about Hannah.
If she's indoor, I'm assuming she's eating cat grass that you bought at the pet store? Grass will typically make cats throw up and they like to eat it when they feel they need to get rid of something, like a hairball. The combination of the grass and hairball could have been the reason she threw up twice, this morning. Here intestinal system may be irritated, and that's why, at first, she didn't show much interest in her food today, but she did eat it.
If she doesn't have any other symptoms, like diarrhea, lethargy, coughing, fever (normal for cats, rectally, is between 100.5 and 102.5) and is acting pretty normal, I wouldn't worry too much for the moment. However, if she should stop eating and/or drinking and continue to throw up, something more serious could be going on. like an intestinal infection, or a food allergy, and she should be seen by the vet in person for a diagnosis and treatment, if necessary.
For the moment, if she's nauseated, you can give her 1/4 of a 10mg. tablet of Pepcid AC (Famotidine) to help settle her stomach, control acid and nausea.
The tablet is very small, so 1/4 can be given in a tablespoon of plain, jarred baby food chicken, containing NO onion or garlic products. Beechnut Stage 1 Chicken is a good one. You can feed it from your hand and after she eats the pill, follow it with a little more baby food. You can also hide it in a small amount of her wet cat food (also, feed from your hand) or Pill Pockets, by Greenies, a soft cat treat, made to give tablet medication. It's soft, like 'Play Doh', so I'd rip a piece off and see if she likes it and then wrap another piece around the 1/4 tablet. You can do this every 12 hours and see if she returns to normal. If not, you always have the option of the ER vet, since this is a weekend and your vet may not have emergency hours.
I hope all will be well with Hannah!
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