Im know of this sixth sence you are taking about ..
At the moment one of my cats is not feeling that great ..the other one Mr chezwick has picked up on this . Normanlly these two dont show a great deal of personal effection towards each other..but the other
morning I noticed that Mr chezwick was giving Thomas a wash..Plus that evening thomas was seen cuddling up with Jazz my greyhound..So maybe there is a certain sence that animals can pick up about each other..
As to your mother with this visiting cat..maybe he has picked up a different sence that there is no longer a cat in your garden and moved in on a vacant territory ..and possibly a new home...
Good news for both..
Julie