Your temp readings sound fine. You don't want the top of the bedding to reach 90F because that means the glass surface will be 100F+. A surface temp on the glass of 91-94F is a bit hot but since you've got substrate to block it off it should be fine. Even if she pushes the bedding aside, 91-94F won't burn her. I would potentially think about lowering the temps so they fall a bit closer to 90F but your current readings sound great.

As far as for the ambient heat there's no reason to ditch it if you don't want to, just get another thermostat to control the lamp. I would honestly suggest a CHE over a light, since you can leave it on 24/7 without disrupting their day/night schedule. If you keep the ambient heat, whether you choose to stay with the light or go with a CHE, it needs a dimming and pulse-proportional thermostat. ON/OFF thermostats can lower the lifespan of a CHE, and a light definitely needs dimming so that it's not just repeatedly turning off and on.