Norovirus - Vomiting Bug

MY two kids came down with the winter vomiting bug on saturday afternoon.  My 7 yr old seems to be coming out of it today but my 2 yr old is in a bad way.  she was getting sick all day saturday and it stopped late that night.  she got sick again yesterday morning and this morning after drinking some water.  she does seem in ok form and is watching telly but i thought we would have seem her improve today.  is there anything i should be doing apart from trying to get her to drink. she hasnt eaten anything since saturday morning either. the doctors not in till tomorrow and i wouldnt think shes that sick yet that she needs to be on an iv but im starting to get a bit worried about her thanks