Putting to sleep awake...

ns1

Is it okay to put a 5 weeks old in her crib while she's still awake (drowsy...but with eyes open or partially open) and leave her and just hope she'll fall asleep?  I have started doing this because after 1 hr. of rocking with no success at 3 am I get a little impatient.  Sometimes I wait out the little whimpers that follow too and wait to try again until I hear an actual cry.  I feel kind of bad, but sometimes this works and she ends up falling asleep on her own.  Anyone else put LO down at 5 weeks without them being fully asleep and kind of let them get themselves to sleep despite a few whimpers?