I don't think more chicks would be any more effective at breaking her broodiness. And you would have the trouble of trying to get her to accept them.
I don't know for sure what is going on, but you might try moving her and the chick to another pen. Even something like a dog crate would work, although more space might work even better. Sometimes a change of scene is enough to break a broody, especially after she has sat for that long.
If you try moving her, do it when you can be there to watch what she does. I would do it in the daytime, so she is more likely to get up and explore the new place rather than continuing to sit. I would not provide a real nest, just a safe floor surface. She can sit down and warm the chick anywhere she wants.
If she paces back and forth and steps on the chick and ignores it peeping, that's a problem. You might have to put her back where she was before, or take the chick and raise it yourself.
If she sits quietly with the chick underneath, she may snap out of it once she has a few days of no eggs (because the other hens cannot keep providing her any.) Or she might just keep sitting there. That doens't hurt the chick, as long as it comes out to eat and drink, but obviously that doesn't solve the problem of her still being broody! If she does that, I'm not sure what to suggest next.
