Well cull her. You don't like her, she is mean to the rest of the flock, she is mean to you. Go in at night, take her off the roost with a towel covering her head. If a bird is not working in the flock, out that bird goes.
You may have to keep the 1.5 month old chicks apart from the flock until they are full grown. They have been kept like a separate flock.
Yesterday, my broody hatched. She was never separated from the flock. This morning, she took the chicks for a walk, taught them to drink water, peck a little food. The gate was open, but here came the Rooster and the layers, because my flock is multi-generational, they have all been around chicks before. They were curious, and they do look at Butter like, "Oh no, not again?" But it is the easiest introduction.
The only way to go.
Mrs. K