Odd Wifely behavior.

My wife hums when she's asleep. 

This is new but it does not seem to be cause for alarm.  She just hums.  It's never really a song I recognize.  She hums a little tune to herself and the baby. 

She's been having such a difficult time sleeping so rather than wake her I just let her do it.  She's always been able to sleep through anything.  Not this.  This is an entirely new thing. 

I have passed my insomnia on to her. 

However, when she does sleep... she hums.