Normal Pecking order? Or too much?

I have 6/7 week old pullets that I put out in a separated run during the day. I have two older hens (an EE and a buff brahma). I was honestly worried about the EE bullying but she was ignoring the babies. They all seemed okay so I cut a small hole that I thought only the babies could get thru if they needed a reprieve. Well, surprise, my gigantic hens squeezed right on thru and EE was fine but my brahma is pecking the babies. Im not sure if its normal first time being together behavior or her bullying. I was hoping they could all go in the coop tonight, but now Im probably going to just bring the babies back in the house because Im worried about this pecking, but I have no frame of reference on if its acceptable pecking order stuff. Video attached.

My likely course of action is to close off the hole and keep them side by side for a few more weeks. Kind of bummed because, like I said, everyone is getting along great but the brahma.