I wouldn't put fresh eggs under her. That would have her sitting 3 months. That's too long. Plus, if she does finally decide to quit, the embryos are dead.
I would do chicks or break her. If you get chicks that are young enough, you put them under her immediately after dusk, she will protect them from the other birds. What breed is she?
The reason I say, if the chicks are young enough, is that as they age they quickly become independent and may not bond with her but it usually works.
Sometimes hens will quit and sometimes they won't, often depending on the breed.
Even if they do eventually quit on their own that excessive time without moving and limited food and water isn't good for their overall health.
I have a friend who always had broodies. Silkies, cochins, seramas and turkeys.
She never took any action to break their broodiness. About the only thing she ever did was to put some of my fertile eggs under them. One of her turkey hens stayed broody for over 3 months. By the time she decided to intervene, the turkey couldn't move on its own. After 3 months of physical therapy and $2,500 of vet bills, the hen died.