I would suggest playing thunder storm noises to her when she is outside or eating, when she is calm and happy. Much in the same way you would socialise a puppy to different noises. If she is used to the noise when she is calm and enjoying herself she won't worry so much in a real storm. I did this when I first got my tri Rex Missy (and her sister at the time). They both freaked out at the sound of car alarms or engines revving etc. I took my laptop into the shed for a few nights and played sounds of car alarms to them, very quietly at first and getting louder as they got accustomed to it. They don't bat an eyelid if the car alarm goes off now. I would also get a heavy duty hutch cover to put on in the storms, just to keep her warm and dry and hide her from the lightning a little bit. And of course give her plenty to munch in a storm to keep her mind off it!
