If she is pooping, things are moving through. There’s not a lot more you can do now, except make sure she moves around and keeps warm. (If she moves around and eats by herself, she will keep warm in normal room temp. Cisapride (a motility drug) and metacam are drugs that are commonly prescribed for rabbits, I’d keep giving those.
You can give 1 ml simethicone baby gas drops, since gas tends to accompany any stomach upset in a rabbit. It’s harmless and not absorbed into the body, it stays and acts locally in the gut until it’s pooped out. It may not help, but it won’t harm, according to both Medirabbit and Dana Krempels.
If you are very worried, you should of course contact your vet again.
It is nowadays believed that EC can affect the gut. You could ask your vet about that, they might think it reasonable foryou to do a course of Panacur again. EC is typically not completely eradicated by the standard 28 day treatment, so this could perhaps be a flare up.