She shouldn't be too intent on continuing this behavior much longer, but I've been surprised before and take no chances. She is happy with this location: Take one egg per day (mark a couple and leave them) and she'll continue to lay there. If the nest is too disturbed she might well take off into an area that is more difficult for you to access and/or more easily available to preds.
In the spring (when hens get serious) it is a good idea to have a safe nesting area arranged before they start presenting to you or the toms (lie down in front of you - if you pick them up they'll be `purring') otherwise they can wander off pretty far in search of a good nesting place. If you are around when the hens go into egg-laying mode you'll see the hen start wandering in a distracted fashion, making forlorn, regularly spaced, `whoots' as she goes. If you just happen to see them wander back in the evenings to range, or hang around, with the flock (what you just described) it indicates she's just working on gettting the egg count at the nesting location to the `magic' number, and it will be time to track down the nest and move the eggs. If you wait until she sets, and her nest is in a thicket of thorny vines, it can be a challenge to move her (even after dark).
