Given the weight loss, I'm glad you have the Hills A/D.
You can add a bit of acidophilus to what you're syringe-feeding her -- essentially the active ingredient in BeneBac. Pharmacies or places like GNC should have it - find the capsule version in the fridge, pop open the capsules, and sprinkle the contents into the A/D or on her kibbles.
I'd try offering sweet potato and butternut squash baby food. The gold standard for problematic poops, in general, is unseasoned pumpkin puree. But I find that harder to find and store... easier to have multiple jars of baby food around.
She may be rather dehydrated. Make sure you're syringing fairly wet A/D. Or just some water... carefully, of course. You don't want her to choke.
Ask your vet if treating the symptoms with Kaolin/Pectin (feline version) is okay. I've used that before. Do not use the human version... you know, like Pepto Bismol or what have you - they have added ingredients that aren't good for hedgies.
Get a water filter for hedgie's water -- just in case there's something coming through your pipes that's okay for humans, but not so good for hedgies... particularly a sick hedgie.
I've dealt with hedgie diarrhea... in our case, it was giardia. The key to that (in addition to meds) was to clean. Super-clean... insane clean. Here's some thoughts on that:
Every few days while she's being treated, clean her cage. Not just regular clean. Super-duper mega clean it. And everything she has been in contact with. If you have just the one cage, create a temporary cage out of something like a Sterilite tub (make sure it's roomy and the sides are tall enough that she can't get out). Scrub the new cage out one day (go ahead and use the harsh chemicals... like bleach), rinse it out, let it air dry; next day scrub with water, rinse, rinse, rinse, let air dry; third day, I usually wipe down with a babywipe, let dry, then fix it up with blankies and put hedgie in. Now she's in the temp cage, clean her regular home -- use the chemicals, rinse well, let air dry. Next day rinse, rinse, rinse, air dry. Following day, I'd wipe down with a baby wipe, let air dry, put her back in her original cage. Start cleaning the other one.
Meanwhile, do laundry like there's no tomorrow... Put her fleece in the wash all of it. Her towels, blankies, all of it. Even the stuff that's "clean" now. Use hot water; vinegar. Tumble dry on hot. And super-wash all the rest of her things - dishes, igloo, wheel... Dishwasher on hot is helpful. Let it all air dry. Anything that you can't wash/otherwise superclean (say, like a wood hidey-house) get rid of it. The shirt that you're using when you hold her -- that goes in the laundry too -- you'll want to choose your shirts carefully; else your favorite sweater is about to become very, very small.
