I don't think Silver is being an arse.
Before people have children themselves, to them, asking how a baby is would be like asking how someone's cat or dog is.
Parents and husbands and older children do stuff but babies don't. They lie, they roll around, they cry, they poo...
Of course, when we have them, we realise that they are amazing little people right from the start and that you can see their personalities grow and that they amaze you every day by every single little thing they do.
But until that point, people don't know that.
I remember before my son was born, my brother asking me how old he'd be when he started being interesting. He just had no concept of what a 'baby' would be (neither did I really, I think I said I didn't know!) and then, at my grandma's birthday two weeks later, he said he couldn't believe he'd ever asked that question because he was already fascinated by everything he did.
The OP might feel better about it if she were to understand this. And, like Zany, I don't think I'd have noticed if people asked or not.
I still think being so upset she left the restaurant was an over reaction.