I guess she feels safer in her crate and figures we will handle it .

Except my Darla is my youngest daughter I do also have a mixed breed, Mighty Dog, who is afraid of thunderstorms. I read that instead of petting them and telling them it would be okay, to instead get a toy and start playing with them. It works great for Mighty Dog during the day. He hears thunder now and runs for a toy. During the night it's a different story, he jumps up on our bed and trembles.

Betty, Buddy and Mighty Dog

We live outside of Ft Hood and she can't tell the diff from thunder , helicopters, gun fire, we attack it all.

baby being a 2-3 year old rescue have no idea what her prior issues were....I know once we pretended we were checking out the house with the lights on she calmed down....she really is not fond of ANY annoying loud noise...she attacks the vacuum and if a truck goes by the house she barks until you can no longer hear the truck

if you make a big deal about it they will worry more...the distraction with a toy is an excellent way to start associating storms with something ggod...
....every time we get a huge thunder clap the yelps all look at me..I don't even glance up (that they see.).and they go oh okay...and go about their business..but they do always check me for my reaction...except MoJo..he goes to the door or window...and every single loud clap gets on growly boefff..then he waits for another...and repeats it
I watch to see if he checks out my reaction...nope and nada..he is in his own little bullie world...beofff.....lol..c.e