It's not an over reaction if she's not eating. If there are signs of bloat, diarrhea, heat stroke, it's been more than 12-24 hours since a rabbit last ate, or other critical signs of deterioration, that's considered an emergency.
I would first make sure it's not from excessively high environmental temperatures and a high body temp, which could be an immediate emergency if signs of heat stroke are present. Then if that's ruled out and she's acting normally but is just not able to chew, a dental problem is most likely and does need to be addressed right away if she's not eating much or anything. Pellets/nuggets softened in warm water(made fresh) can sometimes help get a rabbit eating a little until it's time for the vet.
If she is instead acting abnormally and lethargic along with not eating, and it's not due to heat stress, then it could be an upset stomach. In this case, I will usually try 3 doses of baby gas drops(simethicone) an hour apart each, in case of minor to moderate gas pain, and see if that helps. But if by soon after the third dose my rabbit isn't back to normal, that usually means it's time to get to the vet straight away as it's something more serious.
Also making sure a rabbit is warm and not hypothermic, which can happen when a rabbit is feeling unwell. I will feel the ears and if they feel really cold then I will use a rabbit safe warm pack to try and help warm up my rabbit(really hot ears would mean heat stress and a warm pack should not be used but cooling methods instead, or vet immediately if signs of heat stroke). If an upset stomach is suspected, gentle belly massage and encouraging movement can also sometimes help.
https://rabbit.org/gastrointestinal-stasis-the-silent-killer-2/
https://rabbitwelfare.co.uk/rabbit-...abbit-friendly-vets/rabbit-friendly-vet-list/