Red eared slider's lines are expanding, look about 3mm wide and she scd her shell. Is this shell rot?

I've had her since Aug. 6th. She's in a 10 gallon tank w/submerging heater filter clamp light w/60 w bulb fluorescent light w/17 w bulb. The dark lines going through the green of the shell look like they are getting wider in size and I noticed she sc the top point of her shell. Is this normal? The shell also has a small gray patch in two places on the shell, please help!!!