Leghorn stole the nest

[BreeShu]

As the title says, I have a white leghorn who kicked my broody senior mutt mom off. She had already been sitting for over two weeks and had proven to be a good mom in the past. I noticed in the last two days, one of my younger leghorns has booted her and taken over. I'm not planning to interfere at this time but I am concerned as I've read leghorns are not great moms. This hen is young and flighty, she flees as soon as I enter the run. She has been so aggressive with my senior hen, ripping feathers out till she gives up the box and I can tell a couple eggs were crushed in the disputes. Should I just continue to keep watch over this final week or intervene and see if the senior will go back to constant sitting?