Well, reptiles are cold-blooded, so what happened was that she stayed cold for long enough that her body temperature dropped. It's not great for them, but it won't kill them instantly either and just being cold to the touch is definitely not a sign that she is dying or dead. I took my boy with me Trick-or-Treating, tucked into my costume against my body so he'd stay warm. That worked perfectly... until it started to rain on the way home. I got home as quickly as I could but my poor baby was a soaking wet dragon icicle.
He even shivered! But I immediately put him in a nice hot
bath and let him soak until the shivers went away, his body felt warm, and he wanted out. Then I took him and put him on my computer monitor (which is as hot as a normal cage basking spot, 105-110), and moved his UV lamp over. He was back to normal pretty much immediately. I was very worried he would become ill because of that experience, but it's been over two weeks since Halloween and he is doing just fine, so I can safely say that while I will never allow him to get that cold again, it doesn't seem to have done him any real harm, long-term.
As to the bulb burning out, that's exactly the sort of contingency that I have Sunset's heaty pad for. And the other poster is right -- ordinary clear household bulbs put out a LOT of heat so they'll work fine in a pinch for cage warming.
Good luck! You're doing a great job with her and she's very lucky to have you.