It's different everyday for me. Some days I wake at 5:00 am when it's dark and quiet, and write like crazy. Other times I write the whole day away, and get a lot of work done.
When there's a deadline looming, I work whenever and wherever to get it in on time!
PS. Wow - I, too, can't imagine working with 4 kids around! Whew - kudos to you, Cheryl!