I have 4. ages 10, 7 just 3 and just turned 1. Have to say the fourth was not entirely planned! We have no regrets , hard work especially asin first 12 months hubby was away in the week!!
I do agree that once you have 3 moving on to number 4 is not very much more work! Still lots of laundry, no privacy in toilet, etc. We had to get a bigger car though1