i can see a thermometer on the glass and on the wall, which one are you reading the temp off of ? both will give you an inaccurate reading of what the temp under the ceramic heater is. (basically right where she is laying) if that tells you that it is 34c then you should be ok,
OK here come the questions:
if the previous guy wasn't heating her, does that mean you put the ceramic heater in ?
if so what wattage is it ?
the wire that is on the side vent should be on the outside not the inside, she may damage herself on the raw edges, and is that the only vent ? i hope there is some in the roof,
weetbix boxes make good temp hides, dont know if she will fit though, but you get the idea.
You can buy heatmat from the petshop or online, but with the ceramic heater, but she may need to get closer.
you should buy frozen rodents from the pet shop or a breeder, then you now they are parasite free, if you go down they need to be fully defrosted (not in microwave) and fed warm by putting it in a jug of hot tap water.
@ sophie. sand will stick to the prey if its damp and can cause impaction (constipation) which is not a good thing.
Sorry for the epic post, but hopefully its providing some help.....