Is she really lethargic? Are you able to put her in a lukewarm bath to try and help her temp? I know it's probably a bit late to be putting her in a bath though.
Maybe try and give her some electrolytes..the name escapes me atm, but there are iceblocks you can buy which are great for rehydration. If you are really worried about her though I'd consider taking her to emergency if you can get there..little ones can go downhill so quickly. Hope she is better soon, sounds like you've had an awful time of it the last couple of days!