If she is manuring, eating, and drinking, I'd also consider ulcers. The kicking out when you attempt to get close to her belly was a red flag for me, especially since she hasn't had any hay. I am NOT a vet, so please don't take my word for it, as possible colic is so very serious, but I might try giving her a dose of ProCMC. If she has developed ulcers, this will give her a little bit of relief for a short time. If a vet comes out and diagnoses ulcers, get Gastrogard or Ulcergard ASAP!!
I've spent most of my life riding horses. The rest I've just wasted.