Update! Today the chicks are just off 3 weeks old, and I have opened the maternity ward to attempt integration again this evening.
We have a success! Splurt is no longer chasing or pecking the chicks at all and is very much keeping her distance, Paprika likes hanging out with the chicks but whenever she pecks a chick or looks at Bean funny, Bean lurches at and pecks Paprika a little harder than a normal admonishing peck and Paprika wanders off. I would call it bullying but chicks are involved so I am instead glad that Bean found her protective anger.
After that first half hour or so, everyone was simply happily keeping their distance.
I intend to keep locking the babies and Bean separated from the others to sleep for a while longer, as the confines of a coop are a bit much for me to trust a total lack of conflict.
I'll be monitoring for the next couple of days to make sure everyone stays happy and conflict free.
Thank you all for your help and advice, its tricky that every flock really is different and has different requirements, but knowing what others do and what things to look out for makes the world of difference.
But yeah, this is sustainable and mostly routine for all my girls.
