As she is recovering from a prolonged diarrhoea, it will take some time for her appetite to fully recover. Stool frequency should also return to normal over next few days.
Continue same cold medicine.
Next Steps
Advance diet slowly. do not try to force feed.
Give light and healthy home made food only, like curd,khichdi, apples, banana, anar, Dal rice etc
Health Tips
Keep regular follow up with pediatrician till complete recovery.