Introducing new chick to flock

[Lis86]

I have recently rescued a chick who is now 6 or so weeks old. How would you recommend introducing her to my 3 current hens? She has had some day trips outside and they seem fine when separated but bully her when all 3 are with the new little one.

 

[3KillerBs]

Here are some useful articles on integration:

https://www.backyardchickens.com/articles/integrating-new-birds-at-4-weeks-old.72603/
https://www.backyardchickens.com/articles/my-coop-brooder-and-integration.74591/
https://www.backyardchickens.com/articles/introducing-new-chickens-using-the-“see-but-don’t-touch”-method.67839/
https://www.backyardchickens.com/articles/adding-to-your-flock.47756/