I have two gold fish. One of them is absolutely fine but other fish is not eating anything. She sits at the?

bottom of the tank. I tried giving her boiled peas but she didn't eat that too. its been 3-4 dayz now and she hasn't eaten anything. Coup;e of days ago we checked PH level and it was bit high so put that PH solution to bring it lower but she is acting same as last week. pls help me i don't want her to die.