The thing is, you're seeing all those actively reporting their broody issues and a normal broody who stays on the nest is not a cause for emergency/excitement/calls for help.
The typical hen will sit for the whole course. If she's staying on day/night for 2 days she is truly broody and I would go ahead and set eggs destined for hatching under her and not worry about it... until Day 20, ha.
Mark the eggs, set ALL eggs under her at once. Remove ALL previous eggs and also any further eggs added to the nest by other hens. Quite a lot make those mistakes. The hens are not going to wait around for the late eggs. They leave the nest about 12-24 hours after the first chick hatches.
You can wait a week or two for desirable eggs to collect before putting under her. Or any time in next few days if you already have eggs and the number desired. No more than 12 eggs for the typical hen though.
BUT, if you decide to move her to kennel.. do NOT put desired eggs in it immediately. Use tester eggs in case she refuses to brood in there or is not exactly settled for a day or two- sitting but cackling and standing up for moments... Some hens move well to a nest set up very different from their original nest... some hens flip out and refuse. Usually the best luck at moving happens if you do it at night.