I have almost exactly four years between my two, on purpose. I didn’t want two kids at university at the same time! My two are both girls. When I was on maternity leave with the second, my first was starting school and I could walk her to school every day for the whole of her reception year. I am so happy to have been able to do that.
For the first 3 years they played amazingly together, eldest is very motherly and loves babies, and was so happy. The past year they have been more at loggerheads, youngest is such a free spirit and thinks rules are made to be broken! They still have overlapping interests, they both collect LOL dolls and like a lot of the same tv, mostly because youngest likes things a bit older.
Having separate rooms helps, eldest just needs some peace sometimes. They have played nicely all day today, and are slowly getting along better since youngest has started school. Eldest is only just growing too big for soft play now, they love going together, and youngest is just getting old enough for bowling and cinema, so we manage just fine. We also encourage some separate activities, like cub scouts for eldest and dancing for youngest, so they get their own space and friends too.
In terms of childcare costs, I’ve never had to pay full time fees for both ever, once youngest went to the childminder eldest had started school, so financially it was very reasonable to wait.
I think it’s a sensible, pragmatic age gap. It’s suited us perfectly!