Yes, I think Ruairi's yr 8. Oddly enough his boarding school life; parents' motivation, timescale, holidays and exeats have in general been relatively accurately portrayed. Obviously there was an undercurrent of another agenda but Jenny and Brian's worry that he would be lonely at home seemed perfectly kindly and sincere. They did some research, visited, found somewhere they and he thought he'd be happy - no haste, no stress. And although of late he hasn't been mentioned they did start off with a realistic rhythm of days out and weekend leave etc; everyone took it in their stride with no fuss at all.
I don't know why I'm certain Sasha is 12 ... I'd already married her off to one of Frilly - but I guess Ruairi might be a possibility - though less complicated if Doc Locke becomes the next Mr Pargetter.