I think being available to discuss issues with your children when needed is important but resilience is learnt by dealing with things on their own but knowing they have backup when needed. The PFB trope exists for a reason, in some small modern families children get too much attention from their parents and aren't allowed to spread their wings. Larger families allow children to develop beyond their parent's ambitions.
I think that's a rather silly, blinkered response, @CountFosco, from a poster whose views I generally tend to appreciate.
I can assure you I was an extremely resilient child. I had no bloody choice, because it was obvious to me from an early age that my job was not to be any trouble, because the sheer weight of numbers, especially given my position in the family someone's potty-training, someone's measles, producing dinner for ten, laundry for ten with a twin tub and a clothes line etc etc meant there was no space for me not to be entirely self-reliant.
I learned that lesson so well that when something really bad happened (sexual abuse) when I was about nine, it never even occurred to me to tell my parents. I was so self-reliant I had learned to regard my own abuse as another parental problem to be posed to two already overstretched people.
That's really not the kind of resilience I think any young child should have, far less the type that should be praised as the antidote to 'PFB', an expression I find rather naive and self-deluding in its Mn usage. My own childhood made it very plain that you don't automatically become a better parent by having more children.
And as for 'spreading your wings' in a big family -- parenting as non-individuated crowd control is really not that liberating for the children in question. My parents' 'ambition' for us was that we got through school without stepping out of line, found ourselves some safe local job and got married, like a category of items on a conveyor belt.