You literally told me my child was unhappy at being an only child and was hiding it from me.
I literally didn't but I'm happy to clarify what I did say again.
My parents are (were? I don't know if they would talk about it much any more) adamant I was a very happy child. And I wasn't a miserable child. I wasn't wallowing around in pity. They provided everything that any child could probably ever wish for. Both materially and experience wise. Did I feel extreme love? Probably not, quite a well to do, old fashioned, we don't do long talks about feelings, kind of family. But I did feel well looked after. That they were very proud of me. I certainly felt they were doing what they thought was the very best for me.
They were all I had. Directly. Cousins and pals are no substitute. But my parents were adamant I wasn't missing out on anything because I had them. And as they were all I had, I certainly wasn't going to tell them any different. They definitely had the attitude that I was very lucky. And in some respects I absolutely was. Like another PP, my inheritance will be different level. That's not to be ignored. And I do account for that, and the difference it will make for not only my children, but theirs. But I never had the one thing I longed for. And that's not suggesting they should have had more children because I said so. Nor being a spoilt brat. Just longing for what I could see all my friends with, another person their age. To love, to play with, to fight with, to hide with. To get into trouble with, to roll their eyes at my parents with. And as an adult whilst the reasons why I long for a sibling now have changed, they are still there. That's not about a spoilt tantrum because I want and didn't get. It's a real sadness.
My life is good. My life is privileged. But I have, and will always want a sibling. And that's ok.
You have my absolute deepest sympathy. I too, have suffered the loss of a child. Pre term. But that's not for this thread. There may be deeply, deeply tragic reasons why we have the number of children we do. And whilst it absolutely determines the number of children we have, I think it's quite a separate issue in how the parent feels, to how a child feels in relation to being an only child or not. It's a totally different dynamic.