Op, 2-2.5 year age gap is the best if you want them to be friends at a young age. 3+ and the age gap is a little too big.

However, you will be exhausted with a 2 year age gap. The older will still need a lot of help when the baby is born. At 3 plus, they are a little more independent.

We have a 2.3 age gap and we could not be happier. They are extremely close. - it's like having twins without the health risks

We have a 25 m/o and have been trying on a sibling for 5m. We hoped for a 2.5 yr gap but after just having a chemical pregnancy, are looking at 3 yr gap at best. I say all this to echo those saying start trying when you’re ready and you get what you get. The chemical has forced me to let go of, or at least loosen, our vision for our family being so specific. We will love another kiddo if we are so lucky to have them.

Don't try to time this. Your bodies might not cooperate.