Johnny's new pal

Johnny, our ginger cat, never lets any cats near the house without a good telling off and a scrap.
Last couple of days though I have caught him chillin' with this little beauty on the shed roof.
No fighting or shouting, just sitting side by side.
He has never done this before - and strangely she(?) looks very like our other cat 'Pepper' who sadly died in March (see her HERE)