sorry to digress from your post, but how are you checking your temperatures? you mention a 90° F hot spot, but where are you taking that temperature from, and with what? thermometers? probed thermometers? with the UTH being unregulated i can almost guarantee you that hot spot is closer to 100° F if you're lucky; they can easily reach 120° F when unregulated which is extremely dangerous.
the #1 reason a new/young beep won't eat is poor husbandry. you need to get your husbandry 100% on point (which includes getting the thermostat for the UTH) before we try offering food again. once your heating elements are regulated and you're POSITIVE your temperatures are where they should be, then we can try some things to get her eating.