Feliway, For a scared cat and an aggressive cat.

Not sure if there are other threads about this
But I have 2 cats (mother and son) and the mother is a really aggressive cat towards people and especially her son! And her son is so scared of everything And runs and hides when anybody comes over. Has anybody used feliway for either of these problems? And has it worked?

I use Feliway and it seems to help calm Ritz, but other people have had poorer results.

What is the background of the cats?  Is this new behavior (sign of pain, illness) or old (sign of psychological trauma or DNA).

Behavior shortly after playing or seeing birds (redirect agression).

Are these cats fixed, i.e., spayed/neuter?

They're 8 and 9 and they have been like that from the beginning sadly, but prince seems to be getting worse like hiding for hours even after people have left. And princesses aggression is very frequent, I'm not too worried about her aggression in general but more so how it's aimed at prince which is for no reason, he is very timid.