Proud to say after two months and hundreds of flyers given out and posters and trail cameras set, someone spotted our cat 4km away and we got her back yesterday. We took her to the animal hospital and she is doing okay so far. She is currently locked alone in a room and we are supervising her.
However, I noticed whenever the other cats see her in the last day (there is a transparent cat door in that room which is locked now) they start hissing at her and changing their attitude towards her. My cat that was missing however seems to still be happy and wants to play with her old friends again. Why exactly are my other cats so aggressive towards her? They were best of friends since they were young for over 3 years.