Not to make light of poor Sassy, but 101 isn't really a fever for a foal. That is often a normal temp - a good reason to temp your horses and know what 'normal' is. Our foals normally are in 100-101.5 range. Adults are usually a bit lower 99-101.
The diahrrea on the other hand would give me a great deal of concern. Biosponge as others have mentioned works great as well as keeping her hydrated, but erradicating the underlying infection is the problem.
We've lost a few foals over the years to varying causes - why it can be so hard for your vet to pinpoint exactly what's wrong as septic foals, salmonella, rhotovirus all can cause that same (we call it) death diahrrea - that is an immediate trip to the vet and usually time in ICU. We had a foal one year that an ultrasound revealed serious congenital kidney issues too. The symptoms you have described is much different that foal heat diahrrea - color/smell, etc.
Best wishes, thoughts and prayers for Sassy.