Thank you for your query.
Your child has a bad ear infection
.This is a rare side effect of breastfeeding
Your child needs a powerful antibiotic like amoxycillin-clavulanic acid
combination syrup for 10 days at least.
The pus should stop after 5 days.The child will need a mild antihistaminic drop too.
Prevent water from going into her ears during baths.
After she recovers get her hearing tests done after few months.
If you have any further queries you are free to consult me.Hope this answers your query.Wishing your child a speedy recovery.Have a nice day.