That's sad Briony.
One of my sons in law was not treated well by his parents, he's never really got over it.
My mother did have a favourite child, a long list of them, either one of her pupils at school or a neighbour's child.
When my children were little my mother couldn't understand why I was always cuddling them she'd never done it to me so why did I do it? She often asked me this. My dad wasn't particularly demonstrative either but I knew he loved me.