I am the OP, a few name changes on, and I last updated 3 years ago. There are so many awesome posts on this thread from so many lovely people, it's definitely by far the best thread I ever started.
My dd is 17 today so I'm gonna provide some updates!
Did she ever wish for a sibling - nope.
Has she been a lonely child - nope.
My dd has a great friendship circle but also needs alone time and even appreciates time with her mum, not really much different from when she was younger although there's now less of the mum time! We still go on holiday and on city breaks as a family and enjoy this time.
My dd has met with a few big challenges in her life and I feel glad that I didn't have another child competing for my attention and support at the same time.
We have been able to really get behind her interests and support them whilst dp and I have both been working and also enjoying our own interests and friends.
Teens can be a real pain at times and completely delightful at other times; Whilst she can sometimes drive me bananas I have nothing serious to complain about with mine.
As dd becomes more independent and closer to flying the nest, the balance of my own life becomes more about me and my own interests and relationships which I am really enjoying.....although sometimes part of me wishes I could travel back in time for a few days to revisit the simplicity and cuteness of my dd in her younger days!
Dd can be herself without being compared to a sibling or needing to forge a separate identity to her siblings. And she is very independent and used to adult company which serves her well both in the world of work and in interactions with teachers.
Three is an adorable family size, it gives an awesome ability to balance parenting, work, individual interests and friendships for all three of us. My dd wouldn't have changed it.