Oh boy, it sounds like you've already tried most of the things that I'd suggest (we have this problem with Daisy, too

). You're right though, the days leading up to the 4th (and of course, the 4th) are likely to be really, really hard for her & you. Daisy is like my shadow any time of the year, but particularly so this time of year. Most of the time, I just keep her really close to me (or more correctly, she does this by herself

). However, if I absolutely have to leave her alone, I've had the best luck if I leave her in the kid's bathroom (no windows) with a box fan running full blast and a radio playing easy listening or elevator music turned up loud. Even then she ate a bit of baseboard and some door moulding 2 years ago, but she's been ok since (knock wood). Usually it works out fine. . We've been working on this with Daisy for 9 yrs now & it's not easy. I wonder if Jenny has been traumatised by gunshots or other loud noises in her previous home(s). Poor baby. I know that Sam hates gunshots also, but he's ok with thunder & fireworks. Since he was so abused, we wonder if someone shot guns around him. Or if he was a LGD and his livestock was shot & slaughtered around him.

We'll never know. It's sad.
I hope that the vet can suggest something that will work better for Jenny. We tried a traquilizer from the vet for Daisy once and in her case, she just shook & panted nonstop anyway & then afterwards she slept so soundly for so long that she really worried us. So it really didn't work for Daisy, but maybe you'll have better luck with a new med for Jenny. I sure hope so. Our best solution so far has just been to keep her close to me or in the bathroom with the radio & fan (oh & no food just before, either

you can imagine why, I'm sure

). I just wish that I could offer more help than this. Let us know how it goes, ok?