70-75F on the cool end is too cold for a BP, the absolute minimum temperature for anywhere in the enclosure is 75F. How are you measuring temps? You should use both a temperature gun and a digital thermometer. Make sure both the air temperature and surface temperature are correct across the enclosure. You may need to add an extra heat source or increase the temp of the room to get the cool side temps up.
Some tips to try for the next attempted feeding if you haven't done so already:
- Feed at night with the light in the enclosure and the room off (you can leave a bit of light like a small lamp or light from the hallway or another room so you can still see)
- If feeding F/T or pre-killed, blast the rat with a hair dryer on hot for about 30 seconds before attempting to feed. You can repeat this several times if needed.
- Leave the rat in the enclosure overnight (but remove first thing the next day if it still isn't eaten)
- Make her enclosure smaller by adding a divider and cover the front of the enclosure with a towel so she is blocked from view. Keep the enclosure small and covered until she is eating consistently again. Sometimes the extra security from a tighter and more private space helps with non-eaters.