I have these very same feelings, hun Our reasons for our gap are very different though. Our gap is 3 years 8 months. Pro of that gap is DD wasn't jealous, she understood I was having a baby and that I was very very sick, she loved helping and understood her special role of big sister, she was very involved and understood the baby growing, kicking etc, attended scans and had a very clear shot of the birth....somewhat clearer than I imagined!

Cons....I don't know that I have found many, if any. I thought they wouldn't play together and I was worried DD would never have that sibling bond other kids that are closer have but she adores her brother and they play together now, he adores her even more, I think. He laughs at her and follows her everywhere. Her voice was the first he recognised at a couple of hours of age. Actually the con I have found is that now DD is a preschool when she gets a cold it means DS gets it. That isn't something she was exposed to and I find it a bit unfair that he has to be because she is at the preschool age (prior she was only with me).

I cant answer the separation of #2 and #3 from DD but that is a massive fear of mine too.

Certainly not silly to worry