Out of the current crop of athletes, for this years Worlds, I would place in this order;
Kwakye, Onuora, Oyepitan, Porter
I think Kwakye is a tremendous starter for the relay, and she is obviously there. Porter really impressed at CP and her place should be given.
Laura Turner could be a consideration. I know many aren't keen on her relay participation, however, I think inserted in a middle leg, she wouldn't be bad. If Freeman was fit, she would obviously be in the third leg for me.
I would definitely not include Douglas, and I hope the selectors do not. Whenever the baton is dropped, she has the tendency to be there (CP last weekend, Olympics - just two to note). Whilst she does seem to pick up her performance for the relay, imo she's a little bit too inconsistent and unreliable.