I agree with KatC.
If you want to brood with her, set eggs. Do set ALL eggs at the same time so that they don't develop at different times, and separate her or partition her off so the others can't continue to lay eggs in that nest.
The other option is to mark the set eggs with black marker or pencil and pull eggs out, but that still leaves the hen to be disturbed and risks stomping on developing eggs.
I get my best results by isolating the hen. If you need to move her, that can be tricky as many hens literally brood to the spot they are in. I have both moved successfully and have gotten creative with carpentry skills to block brooding hens off from the rest of the flock. Absolutely, the hen needs no interruptions from day 18 to the first week of the chicks lives or you will have ruined hatches and crushed chicks.
I have had Black Stars brood. I've not had a Red Star, but I've heard it happens. It really is a toss of the genetics and very individual for the hen. Some of my first time broodies were some of my best broodies from surprising sources, though, heritage breeds, mutts, Silkies and Cochins are typically prone to brooding.
You never know until you try. And, for obvious reasons, only use inexpensive eggs for a first try until you know that your hen is faithful.
Good luck. Keep us posted. There are several really good brooding threads here on BYC.
LofMc