@Anyonewhoknows - what a lovely attitude from your dd. :)
I have a 4y11.5(!) age gap between ds & dd. They are (mostly) amazing together and do far more than my db and I did, and we have 16 mths between us.
Ds was very excited to be having a sibling (I told him at 5/6 mths I think, so not too long to wait) and adored her from the get go. He sang to her in my tummy and when she was born he pushed her on swings, read to her, taught her things and is immensely proud of her. He does occasionally wish he had his own room though!
He started school 4 days after she was born and it meant he had his own space away from the baby & was never an issue that he was leaving me with the baby. She starts school this year and I do wonder if there will be more competition between them now they'll both be doing school things. On the whole though, I love that they won't be compared at school - I found it hard to live up to a cleverer/better at sport db in the year above me.
Another poster said that this thread shows the difference between parents of /siblings with the age gap - but I think it also might show how parenting has changed over the years? I put thought into preparing Ds for the new arrival, enlisting his help and when he helped (which was often and willing) saying stuff like 'isn't dd lucky to have such a helpful/kind/amazing db as you' to really reinforce the positives. We have the Internet now to help us look at potential pitfalls and prepare for them. My parents wanted my db and I to be close, but to my knowledge didn't do much to improve our relationship, other than saying 'go and play together' - when all we did was annoy each other and spoil the other's games. My dB and I got close as older teenagers tho, so not all bad. :)