Getting on with the cats

Before Nifty's arrival and in addition to the horses, we also have 2 cats at home.
Fedora is 7 years old and spends most of her time sleeping in the office and outdoors at night.
Gidz is 6 years old, spends alot of his time outside or sleeping on the bed when the weather is bad.
Both are rescues and have free access to house via catflap that recognises their microchips.

Nifty is in her house pen when we're out and has part of the garden fenced off for her to "run free" when we are here.
There is no direct mixed contact between Nifty and cats, there's always some kind of barrier between them.
Nifty will run along the fence if a cat (usually Gidz) runs past but otherwise, pays little attention to them (no barking, for example)

With OH, we decided to let cats decide when to approach Nifty and they did stop and stare at the beginning when she was snoring away. However no cat in sight when she's awake and active.
The cats did take months to accept new cat arrivals so I suppose they're in no hurry.

But Nifty is now 16 weeks old and about 9kgs so she'll be even bigger and stronger the day the cats decide to take interest in her, if they ever do. I thought it would be easier when she was a pup and smaller but the cats were traumatised at her arrival and even refused to eat

Any ideas how to educate the 3 to be nice to, and to accept, each other ?

Time and association is the key I would think. As long as the cats have a means to get up high out of reach and they should all be fine, eventually Nifty will realise it's a useless exercise to chase and simply accept them as part of the household.

I'm just wondering if it's the dog or the cats or both that I need to be educating ?
Was much easier with the horses *sigh*

probably both

Keep an eye out for the cats 'winding up' the dog by sitting just out of reach. Not sure if your cats are like that, but the two from next door's sit on the fence close enough that he can nearly get them. I swear they're playing chicken.

It's a tricky situation as the cats aren't in the house so much by the sounds of it, so they don't see each other all the time. Normally I'd suggest meetings with Nifty on a long line, encouraging her to relax and praising her for not chasing, etc. but if they're not actually there much it's hard!