I have a year old toddler she woke up with a swollen eye and a minor fever. We have given her medicine for the fever but still wondering why her eye is swollen

Could be a bug bite. Gently lift her lid and peer closely at her eye for any sign of something else, redness or if she is in pain.

Is she allergic to something? I would get her to the pediatrician ASAP to find out why this occurred.