I have the same as you :-) 4 year age gap then a 12m 13 day gap and then I also have a 2year 4m gap.
Ds1 is 9.6m DD1 5 D2 is about to turn 4 and DS2 is 19mths.
The small gap was hard at times but I loved it and would do it all again. For me the hardest time was when they where nearly 2 & 3but that was also because DP was working away and it was the beginning of my 4th pregnancy and I was soooooo tired.
Any particular questions feel free to ask :-)