Can you lay congested baby down flat ?

This might seem like a dumb question and it likely is… but my LO is 9 months old and has her first cold. She sleeps best on me but sometimes I’m able to transfer her to her crib for sleep.

Can you lay a baby down flat with congestion? At this age if the mucus obstructs airways will she cry or cough?

(We’re doing the humidifier, nose frida, baby vicks etc)

Thanks all!