Ask her if she's training for a kareoke night.
When she says no, say, "No, I thought not."

It could be that she's not aware she's doing it.
(Sivvus trolley collision in the fruit aisle led to a jam, Fri 25 Nov 2011, 16:42, 1 reply)

i think that is the case, she does have a good sense of humour, but this is tied in with the fact that she's a woman, so would probably take anything i say with a bit too much sensitivity...

maybe i should just badly sing louder? then i could say i was just joining in with her?
( Ya What Skiddlyboop, Fri 25 Nov 2011, 16:47, closed)

Just close the kitchen door, you won't be able to hear her then.
Hahahahahahahahahahaha /sarcasm
(anonymousreality tickled your fancy on, Fri 25 Nov 2011, 16:52, closed)

Just say, 'did you know you were humming?"
Generally if people do it absentmindedly, drawing attention to it will make them realise they're doing it enough to stop for a while.

EDIT: And can I just roll your eyes at the woman comment? I hope you meant it sarcastically. ;)
(Sivvus trolley collision in the fruit aisle led to a jam, Fri 25 Nov 2011, 16:59, closed)