No matter how long we waited, we did not feel ready. There was always too much to do, it was never really the right time. At some point we just gave in and perhaps we should have done it sooner.
Having kids in a later stage has a lot of advantages. You (hopefully) saved more. You are more mature and informed. You know how to save for your children from day one and what to teach them.
But the thing about time is true and doubly so when it comes to grandparents. First of all if you live around your family and they can help out, it's an invaluable rock to lean on, and of course if you waited the grandparents are going to be too old to really help. But what's worse, is your kids will probably know them for a very short time if they even remember them when they grow up.
The thing about "being ready" is nonsense because you can't be ready. You don't understand what a massive gift and blessing it is to have children, and also how everything changes. You can't be ready because you just can't understand it before it happens. So waiting for the perfect time is useless. If you know want children at some point, just do it.