Kelly,

Are you keeping both Phoebe & Emma (Samson) ?

As if one or the both kittens is to be rehomed then that might be enough to calm the house.

Otherwise what about installing a cat flap though the balcony door to your outside run, again by extending the territory your cats have access to might help.

Kelly, how much of this incident was a one off or is this a permeant change of attitude. Is Olivia very upset now ?

What about ringing a cat behaviourist for a free advice ?

Keeping my fingers crossed this works out