Oil and battery

On my moms 1998 chevy camaro. I looked over at the gauges yesterday. I seen that when we sit in traffic that her oil pressure goes down to 20. I looked over at her battery and it goes down into the red on the low side. The battery is brand new. When she drives the oil pressure goes to about 40 and the battery goes to about 10 or 11 volts. I figured it was because we had the a/c on full blast the radio on and she had her phone charging. The oil pressure gauge needle wobbles back and forth when you are sitting still when you drive it does fine it doesnt wobble anymore. The car smells like it has an oil leak. When you shut it off it you can hear something dripping down and burning off. Any suggestions.