I had mine at 19, 25, 27 and 29.
I know I started really young, and that was unplanned, but it was probably for the best. I have a traumatic past and spent my teenage years in self destruct mode, dropping out of school and courses, "partying" was totally out of control and more akin to substance abuse than anything else. I had lost all direction and hope tbh.
Then my eldest came along and I loved him and it gave me a massive kick up the backside. I got a job in a trainee position and had worked my way up to being senior by my mid-late twenties. I got help for my mental health, and although it was hard at times I had endless energy, we did a lot together and were and still are very close.
I met my husband when I was 22 and we married a few years later and had finished off our family. I'm in my early 30's now and ready for slightly older kids. We have our dream home and our jobs pay well and are secure.
We are turning our focus to pensions and investments now and glad to have all the maternity leaves and expensive childcare out of the way. We plan to do a bit more travelling in our 40's and 50's.
It isn't for everyone, but it worked out well for us. I dread to think where I would be if I hadn't of had my eldest when I did. Comparison is the thief of joy, im grateful for what I have.