Just adopted 2 neutered Maine Coons, one 2 year old male and one 3 year old female.

Before that I had 15 year old neutered male MC who died in March. In addition we were adopted by a female neutered white cat who has gradually gone from totally wild, living off frogs and mice she caught and food we put out to coming in during day to sleep with our now deceased MC, but wanting to be out at night, whatever the weather. This over a period of about 5 years, I think.

The 2 year old needed booster injections which he got yesterday. So although the cats had been able to see each other through the kitchen window, I only let the white cat in yesterday - but she is quite aggressive especially to the female MC.

What should I do? What is 'normal'? Although the white cat has never been particularly friendly to me, she has let me stroke her in the last couple of months and I do feel a responsibility towards her. I work during the day too, so for the moment white cat is outside.