The short answer: Yes, but only occasionally.
The long answer: A peanut is a type of a legume crop that is high in magnesium and iron. Technically speaking, peanuts are high in protein, but cats need protein derived from animal meat, so feeding her peanuts regularly won’t benefit her.
Cooked peanuts can be fed to your cat sparingly as long as it is not prepared with salt, sugar, onion, garlic, and other harmful flavourings. Chocolate-covered peanuts are also a no-no. Be careful in feeding peanut butter to your cat, since it can contain harmful ingredients and additives.
How to feed peanuts to your cat: Be sure to unshell the peanuts before feeding it to your cat. The tough, outer husk may cause airway or intestinal blockage. You may choose to serve it raw or boiled without any seasoning.
If you’re feeding peanuts to your cat for the first time, give her one piece and observe her for any allergic reaction. If she is allergic to peanuts, she may exhibit the following symptoms: skin irritation, vomiting, diarrhea, and/or other gastrointestinal issues.
In summary: Cats can eat peanuts once in a while as long as they are unshelled and unflavoured. If you want to include peanuts in your cat’s diet, it is best to discuss this with a veterinarian or an animal nutritionist beforehand. It may do her more harm than good depending on her health condition.