Toddler germs 😑

The inevitable happened. My toddler daughter who started pre-K3 caught a cold the second week of school. And guess who she passed it on to!? My poor not even 2 month old baby 😩. Advice. So she definitely has a cold, she’s been sneezing, some coughing and very fussy. No fever though. Do you guys take ur babies to the doctor for this or only if there’s a fever involved? I heard if they are younger than three months they should be looked at?