when are you able to get her to the vet? do you have baby gas drops? right now, encourage hay.

This is to be taken seriously. It could be a gut slow down causing gas build-up and pain, inappetence and further slowdown. It could also be a blockage, but that’s less common.
If you can’t get to a vet the nearest hours, I’d recommend you to try baby gas drops (simethicone) and a light tummy-massage. Also try to warm her up. That she’s lying still and her ears are cold indicates hypothermia. Hypothermia promotes gut slowdown and is very dangerous. Wrap her in a fleece blankie and sit her in your knee.

A bunny that won’t eat needs to be syringe fed pellet slurry or sth of the kind -this is however risky if there’s a blockage. You can try giving her a little water by syringe, but go slow and make sure she swallows.

A vet will probably warm her up, give her sub q fluids and a pain-killer (gas is very painful for a bun) and possibly gut motility drugs. Then hope for poop and the return of an appetite.

Without treatment this can become very serious very soon. Here is a very good article about GI stasis by Dana Krempels, a biologist who’s a bunny expert. It’s a long read, but it has plenty of great info (don’t try giving an enema though):
http://www.bio.miami.edu/hare/ileus.html
Here’s a nice video on how to massage a bunny:
https://m.youtube.com/watch?v=JnuxGLa2reg

It’s also good if you can make her move about some, that helps gas come out. And by all means try to entice her to eat something, anything is better than nothing.

The fact that Athena was fine after you got home with her during the previous vet trip, may have meant that she had gas and moving around and the motion of the car got rid of it. It’s always good to keep infant simethicone drops on hand to give to rabbits if they aren’t eating or are hunched over or seem uncomfortable. You can get them at any drug store or a grocery store. The brand I have is Mylicon. They are harmless to a rabbit. The dosage is 1 -2 ml every hour for 3 hours.

Even though she doesn’t like it, it might be helpful if you can give her a tummy massage. You could wrap her in a towel, and that might make her more still.

Is she drinking? You don’t want her to get dehydrated. You may have to give her some syringes of water to drink. A vet would give her fluids as part of a treatment for GI stasis, along with a motility drug and some Critical Care for you to feed to her. You can make your own mash to put in a syringe, by wetting some pellets, although it doesn’t have all the nutrients that Critical Care has. But try the simethicone drops first and see if those help.

How long has it been since she last pooped?

So glad to hear it!!!

It’s important to get as much hair as possible off them when they are shedding – even if they don’t appreciate it. If she has “normal” hair or rex fur, you can lint-roll her after brushing. It’s very effective (although you need lots of gluey paper) and many bunnies don’t mind. Mine don’t mind, so I think it’s a really good way to minimize the amount of environmental fluff. I use a generic brand lint-roller, name brands can have too strong glue.