Hi Kristina, glad to see you back. And I just wanted to say that I'm far from an expert but have successfully dealt with a fair amount of fear in dogs.
Her thunder fear sounds pretty much like full blown panic, not just a situational anxiety that they can be snapped out of fairly easily.
The fact that she is coming to you is good. You’re right in not petting, coddling or consoling her but in her panic she is looking for some sort of direction from her leader. In her case, none is coming, she’s simply being shoved away to run amok on her own.
The number one and sometimes most difficult thing to do is remain calm ourselves. It’s quite natural for us to be startled by that first loud crack but then we know what’s happening and our heart rate and temporary fear decreases with that knowledge. Your dog's does not.
Mom got startled, it terrified me, something terrible is going to continue to happen, she could be startled again at any time, she’s shoving me away - panic, panic, panic.
You need to start leading her and giving her choices for appropriate actions as an outlet of that fear. You don’t want her shutting down, you want to work her through it.
We also need to change our outlook. A game I play with myself (hubby’s learned it to) - Big bang, I just won the lottery, no more worries, time to go celebrate. I hear a thunder boomer and reach for that calm, peace right away – in fact I’ve done it so much its actually a trigger now – love storms (sort of – the non lethally threatening ones). Come a major disaster, I want my adrenaline to kick in and the boys are free to read that in any way they please as long as they hussle. I'll work on their calmness the moment I regain mine.
In your case, right now, you simply need to give her an outlet. Be her attention target. Food is rarely an option but exercise on a long line is. Get up and calmly walk around with her. If it’s too miserable outside, up and down the hallway, arrange some clothes in your drawers or closet, show interest or get excited with boring things. Check the leaf on a plant, fill her water dish, wash a small window – you know easy boring stuff that just gets you and her moving.
The time she starts to relax and really focus on you, 10 – 15 from what you’re saying, is golden time. This is where you will start to have an impact and this is the time you are looking to decrease. Out with the great toys or treats, fun games she likes, even start with simple obedience – no corrections during the panic phase. Every inch at a positive attempt is rewarded. Total fun, best time of her life.
It’s difficult work in that storms are so unpredictable and you need to be there but grab every opportunity you can. You’ll find that 10-15 minute settling time starts to turn to 14 minutes, then 13, then 9, then 3 to almost instantaneous, as long as you’re the calm, fun rock when that thunder hits.
My shepherd came to me afraid of his own shadow, terrified of thunder. He hears thunder now and it’s straight to the toy box – come on mom, let’s go. And I always oblige because I know what the alternative can be, not something I want my best friend ever going through again. We’re at a point now though that I ask for a whole string of commands and I’m extending his “long down” before the toys come out. I’m extremely confident that one day I won’t be tossing balls at midnight in thunderstorms – but up until now I remain consistent with this, because it works for him and it’s paying off big time.
A lot of work but anything worthwhile is.
As for the gunshots, I would take much the same approach. John’s recommendation is good but the starter pistol (any firearm you may own) near the dog would be a “final outcome” for me, something you’re working towards. Right now, with a known phobia, it would be much like flooding a terrified dog. Not something I would be doing with this dog.
I could go on but this post is far too long already. I dug up this old thread where I described a method I use with my dogs and a few others that were having difficulties. Not specific to your situation but it might give you some insight into the approach I use and I get to stop typing.
http://leerburg.com/forums/ubbthreads.php?ubb=showflat&Board=134&Number=300355&Searchpage=4&Main=27844&Words=target+range&topic=0&Search=true#Post300355
Please feel free to ask any questions or throw out more information about your specific circumstances and what you have access to.
Hope that helps a little.
eta: Oh and I'd take the wind chimes down for now. Once you see her starting to build some confidence you can slowly start to reintroduce them.