As teenagers, when siblings fight over trivials, I had to step in and mediate. I have seen and read enough to realise that if left unsettled, they might grow up despising each other. When disputes erupt, I would constantly question myself. Is mediation needed? Would the situation exacerbate. Girlfriend confided that, mum favours her sister who is smarter, earning more, than her. As a result both can't stand the sight of each other. Back stabbing and bad mouthing. Sibling rivalry ensue. Worst fighting over family matters and dragging dirty linens into public.
I want my 3 children to realised that at the end of the day, when we parents are no longer around, it's siblings that will be around for each other. As we break into smaller family nucleus, they have only themselves to call upon as Family.