Definetly get a hygrometer! What's the ambient temperature in her cage? Otherwise everything seems ok. You might want to upgrade to a bigger cage soon. And replace the compact light fixture with a linear bulb with a reflector.
Also, do you hand mist at all? It's important to gently directly...
Sometimes you do all you can but still everything won't go your way. I am terribly sorry for your loss. Our family is sending you strength. Don't blame yourself.