I Have An 11 Month Old Niece. She Has Been

I have an 11 month old niece. She has been diagnosed with a Respiratory Infection. We have been in and out of the ER, as well as with her PCP. My niece is no longer swallowing the medication. The doctor's just prescribed suppositories to eliminate the fever. She has been very sick since Friday. The doctor's said that even though she is declining food, as long as she is hydrated, she will be okay. Is this true?? what should we do??
Best,
ConcernedAuntyJ.