Sounds like she was in a sorry state
UVB - well people debate about that. It's not essential
, they can survive purely on a dietary supplement of D3. However, UVB definitely has its benefits. If you're able to provide her with one then I would, it could well help with her recovery.
Heat mats should get a lot hotter than that. Is it an old heat mat, is it attached to a thermostat, what thermometers are you using and what kind of tank is she in? (Lots of questions I know but there's logic behind it all, I promise
). During the day she should have a hot end of around 88-95F, this can be carried on 24/7 if you don't wish to drop her heat at night. Don't increase the size of the heat mat, it doesn't increase the temperature they give off - keep the size to around 1/2 - 1/3 the floor space of the tank.
If she's little it could be worth feeding her every day (but that's your call, depends on how easily stressed she is and you don't want to stuff her silly!). Keep with the variety (try and add in some locusts, silk worms, calci worms and cockroaches if she'll have them) and remember to dust and gut load them appropriately. Many geckos don't go for the bowls, you can try adding food to make the worms wriggle more but that doesn't always work. You could try dropping them outside the hide she's in, often that catches their attention; tong feed or let them loose around the tank at night and remove during the day (if you do that leave a bit of veg so they don't nibble her).