My 4 week old baby has a cold. blocked nose,coughing and is throwing up mucus with her milk. she does not have a fever and is drinking very well. her sleeping pattern has not been affected and she is giving 5 wee diapers and 3 poo diapers every day?

Continue feeds: Monitor temperature and if her rectal temperature is 100.4 F or higher, please see your pediatrician for additional testing and evaluation. Nasal saline drops/coo air mist and gentle suction may be used to reduce post nasal drip and to open nasal passages. Infants breathe through their noses and congestion may result in distress. Please see your pediatrician.

Monitor and humidity: Without any fever, and everything else sounding as good as you describe, you really can just monitor the infant. Use a humidifier and use saline drops along with her bulb suction to clear out her nose. If she starts to run fever or starts not eating well, then baby needs evaluation. The vomiting likely related to the mucous drainage, and although it seems a lot, she is keeping down enough to pee