Another hint hopefully you will find helpful, if you can isolate her from the other hens, it will make things a lot easier. Because the other hens are going to keep adding more eggs daily, which you will have to work to fish out from under her, while trying not to break the marked eggs.
Also, if they give her more than she can cover well, it can be detrimental to the ones you want to develop. She may push those aside to sit on the random new ones.
And last but not least, when the chicks start to hatch, if they are not separated and protected from the other hens, they will be in danger of being killed. Because the broody will likely not get off of the unhatched eggs to protect the first chicks. And it can take a day or two for the chicks to learn to obey the broody and come back when she alerts them to danger.
Many people (including myself) have tried to let a broody hatch within the community at large, and many times the above situations have occurred. If you can put some kind of barrier around where she’s sitting, or move her to her own coop/dog crate/what have you, the whole process will go better. (If you use a dog crate, make sure the chicks will not be able to squeeze their way out.)
Good luck, watching broodies raise their family is fun! After a few days or a week for the chicks to bond with mama, they can be reintroduced to the flock, and mama will teach the other hens to keep their beaks off her babies. And your rooster will likely be a good father and help the mama raise them.