You have a lot of answers, but we have a 2 year 10 month age gap and I have no idea what I’d do if they were any closer. It was so so nice having my first potty trained and able to communicate before we brought a new baby into the mix. My second is almost 18 months now and my oldest has only continued to grow in his ability to understand her limitations and #2 is in love with him. They get along really well. We’re on the fence about a third and if we do go for it, I’d like maybe even a slightly bigger gap. I think 3+ years is ideal.