Is there anything i could do to relieve nasal congestion for my 1 week old daughter ?

Salt water: You can use gentle irrigation with drops of Normal Saline (like artificial tears) and suction with a bulb syringe.

Nasal wash: Nasal saline is available over the counter & provides a valuable aid to rinsing the irritants, perfumes, dust & other offensive material off int inside of the nose where it causes swelling and drainage. It must sometimes be used aggressively to provide adequate volume to thin secretions & improve airway function.