Great Tit not incubating yet despite laying her last egg a week ago.

Hello, first timer here... I have a Great Tit nesting in a box, she laid her sixth egg a week ago and hasn't laid since, but she doesn't seem to be incubating them yet and I'm wondering why this is.  Should I expect to see her on the eggs full-time for a fortnight while the male brings her food?  And if so, given that it's been a week and I haven't seen him yet, is this a sign the male may not be around?  Thanks.