Only Child here. The only time in my life I thought it would be nice to have siblings was when my parents died. It would have been nice to have someone who felt as bad as I did about it. But otherwise I’ve never felt I wanted siblings.
One sister, with whom it’s been pretty cool. We did all the sibling fighting and stuff, but we get along pretty good now, even if we don’t talk to each other that much.
That having been said, I do wish I’d had a brother. Enough like me so that we’d be able to understand each other but not enough like me so that we’d have to put conscious effort into putting up with each other.
Oh my god, no! I already have a brother and a sister that I don’t want.
(I actually have two brothers, but I really like one of them.)
I have an older brother and that’s more than enough. I think I would have preferred to be an only child but when I was little, I do remember asking my mom to give me another sibling. I think it was just so I’d have someone to beat up though. 
My dad had 2 kids, a brother and sister, by a previous marriage and they stayed with us for a couple summers when I was around 6-7. I hated my (half) sister, she was, and still is, a total brat. I got along ok with my half brother then but he later became an alcoholic and caused problems for my parents which I can never forgive him for. I’m sure I would have had to resort to murder if we had to spend more time together. I don’t talk to either of my dad’s kids now and don’t miss 'em.
I’ve wondered about that sort of thing too, since my mom lost 3 fairly early into her pregnancies. I’d still be the oldest (24) but there’d been a sibling who’d be 22, then my brother (18) then siblings 16 and 15… I’m happy with the one brother I have,(I wouldn’t trade him either!) but five kids would have certainly been different, better or worse I don’t know. At the moment I don’t plan to have kids, but were I to change my mind, I know I’d have more than one. I remember being an only and it was lonely.
I’m an only child, and my parents are both the eldest, with a younger brother each. For 12 years I was an only grandchild on both sides, and I now have one cousin.
If I have the fortune to be a parent, I will most likely have only one child. I loved being an only child, and really don’t have the time and energy to raise two children and give each one the attention they deserve.
Course, it’s all a moot point till I find a father. Volunteers aren’t exactly popping out of the woodwork.
Corr