I agree that it doesn't necessarily mean your D would in any way miss out. I truly believe in what you don't know you don't miss.
I had a brother 5 years older than me. He was always insanely jealous of me but I now realise my mum had him too young and didn't really bond with him and here was definitely differences in way he a brought up to me.
That is a separate issue but it meant we never played together and were never close at all. I have no memory of being around him unless he was just being horrible to me. I never once felt lonely, I had friends. I never wished for a sister closer in age, or brother.
Now as an adult I would love a sister!! My parents split, dad doesn't keep in touch my brother moved away and never keeps in touch and my mum is hard work although I love her obviously. It would be nice to have a proper family.
Now I have a 6 yr old DS a 3.5 yr old DD and a 9 month old DS.
I had an awful pregnancy and very dramatic birth with DS and vowed not to have another. I was very happy with my perfect little boy.
However, like you, when he got to near 2 I started having all the same thoughts. I also thought about how I felt a little alone without a proper family around.
I 'kind of' tried half hearted once and fell pg right away. God did I worry the whole PG about the PG and birth and had I done the right thing?
It was perfect and I got my beautiful little girl at the end of it. I felt guilty at first about my DS missing my full attention but everyone does no matter the age gap or circumstances.
I watch them running around all day playing imaginary games and really hearty laughing coming from their bedrooms upstairs. I could not have provided that kind of companionship for him. Im rubbish at power rangers verses princesses!
Of course they argue at times but it's all part of it, they are very very close.
A few days ago at the zoo I watched him with his arm around her stroking her hair while she was eating her ice cream, so cute!
I then had a surprise baby 9 months ago. I again worried sick about lack of attention, PG and birth and how the baby might change dynamics.
He was born very easily after one hour! I did bleed but all good in the end.
The two of them LOVE their baby brother and it's so nice to see the excitement in them and him when they are all together.
It makes me shudder when I think I could have very easily have just stuck to DS on his own. We'd be none the wiser but it's definitely better.
Now I just worry that DD hasn't got a sister!!
. - No energy left in me though!