| Those behaviors could mean she's been injured, is sick, or is in heat if she hasn't been spayed.
Sometimes kittens that play a lot can injure themselves by falling off of high places, landing wrong when they jump down, or having things fall on them. Check her over thoroughly to see if you can find bruised areas or scratches/scrapes. Make sure she is walking okay (no limps).
Cats can catch viral/bacterial illnesses just like humans which can cause fever and irritability. Fevers can make their joints hurt and make them feel generally crabby. If she'll let you take her temp, either use an ear thermometer or stick an anal thermometer gently (use KY or petroleum jelly) into her rectum about a 1/4 to 1/2 inch for 1 minute. If the reading is more than 102.5, she has a fever. If she hasn't been tested for Feline Leukemia, do it as soon as possible!
Heat cycles can cause moodiness and irritability in cats as well. Cats come into their sexual maturity at 6 months of age. If she hasn't been spayed, you might want to think about doing that sometime soon. Heat cycles are hard on cats sometimes causing painful cysts to form on their ovaries which can also cause them to feel grumpy.
Does she go outside? If so, she could have gotten into a fight. Sometimes, cats get abscesses (wounds that fill with puss) from fighting. Medical treatment is highly recommended. I've seen some abscesses go fatally wrong if not treated properly.
It would be best for you to get her to a vet as soon as possible to be checked out. The suggestions above are merely to help you narrow down the possible causes for her personality change. All of them require medical treatment except possibly the first scenario if she hasn't broken anything or received internal injuries.
I wish you luck! Please keep us informed.
Regards, | 
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