Well said @JenPen2004 and @Damnloginpopup
The fact most of you are choosing to argue with a 17 old but referring to yourselves as wise, educated adults really proves how massively uneducated and sheltered you all are. More so that her comments clearly hit a nerve with you all. What a bunch of miserable old fools and frankly I feel sorry for your children if this is how you usually attempt to undermine them.
I could not care less what anyone else apart from the OP has to say quite frankly which is why I wouldn't further offer a response to any of them @JenPen2004 all you have done is excite' their mundane afternoon.
OP, this is a tough situation for you. In my eyes, I think I was extremely lucky enough to have siblings. Growing up with siblings, made my childhood so much more fun and enjoyable because I had someone to experience the highs, lows, and all of the in-between alongside someone else. My siblings have all grown up to be my best friends, including the last and youngest which there is a whopping 19 years between us!! I felt very lucky and blessed to have them around when I lost my father a couple of years back now.
Any of my friends or people whom I have encountered, who are only children generally do express how they WISH they had siblings, of course, they are living fine without them. But it "would have been nice" you know?
From what I believe @JenPen2004 was trying to word is that USUALLY children and adults from smaller households severally lack common social skills, which is factually true, I would know this as I am a psychiatrist. Adults, children from singular families are also often stereotyped as extremely self-centered, spoilt and demanding because they have never been taught how to equally share in materials, love and time.
@Rissa1989 I would strongly advise, if this is something you really do want, then speak to your husband again. Reiterate your longing and ask for him to express why he is so against it. In a situation as detrimental as this where it could impact your family, a conversation really is key and you aren't going to find a logical answer on MN, unfortunately, it's like finding a needle in a haystack, they would all rather point score against a 17-year-old that articulates themself far better than any of them ever could. 