Thank you for your query,
Your child seems to have acute gastroenteritis
mostly of a viral cause.
Give sips of oral rehydration solution like Pedialyte to prevent dehydration.
Monitor her hydration by watching her activity, urine output, and oral cavity moisture.
Take precautions while preparing formula feeds to prevent contamination and each feed, use sterile bottles.
Probiotics like lactobacillus
or sachharomyces will help to decrease watery stools
So consult your Pediatrician
for the examination and the treatment.
Hope I have answered your query.
If you have any quries in future you can consult me on Healthcare Magic.