There is a 4yr 6mth age gap between my two. I felt DS1 wasn't ready to have another sibling for ages. When DS2 came along it was great, DS1 understood, helped with heaps of things, and could do alot of things for himself. Not to mention when he went to school it gave DS2 and I one-on-one time together.

Good luck with whatever you decide and your TTC journey.