Introducing not really new chicken

[MyISAbrownhens]

Where are you keeping her at night?
How old are they?

Gonna be tough with such a small space, especially the coop.
How handy are you?

I'd fence off end of the run opposite the coop, 2x4 fencing would work, need an easy entrance for yourself.
Put up some weather protection so she doesn't get rained on. That bin with an entrance cut into it might work as shelter, but block wind and sun too. Keep her there during the days for another week or two. Put her feed/water near the fence. Sprinkle scratch grains or treats on both sides of divider fence...to get them all to eat near each other.

Then maybe add one bird, the 'nicest' one, to the fenced off area with her so she can bond with that bird. Might take some mix and match to find the right combo.

That's all I got for now.

I’m not sure I will be able to fence anything off, Will the crate not work? She’s in a large dog crate right now in the run protected from the elements