My child is 3 years of age and is having high fevers the past 4 days and now isnt drunking fluids she also has been complaining of a sore mouth

Common problem: If your daughter has reached the point she is not taking enough fluids to wet every 6 hours it is time to have her evaluated. This could be a simple virus or strep, but dehydration would be my first worry. Chilled fluids, frozen apple sauce, popsicle pieces, etc can often help with the dry or sore mouth or throat but watch the hydration.

How high is "high"?: And are these fevers breakthrough despite taking antipyretics? Persistent high fevers & now lack of PO intake warrants an evaluation. Most likely a viral etiology- of which the sore mouth could be a diagnostic manifestation depending on its clinical appearance. With decreased PO intake, dehydration is always a concern in pediatric patients - their "reserve tank" is shallow compared to adults.

COVID-19 testing and Strep should be considered. Watch for signs of rash, dehydration, swelling and red eyes. A visit with your Pediatrician is recommended. Encourage soothing fluids and a CRP,ESR and CBC,Differential and Platelets count is also suggested if not improved.