I've had two over 40, and had absolutely no chance of having them earlier - yes, would have if I could, but couldn't.
And am hugely happy and grateful to have them now.
It totally depends on the woman, the situation (support etc), and so on...
In my early 30s I said 38 was my limit, then 40, then after more or less giving up dd1 was born when I was 43, and dd2 conceived when I was 45 (born when I was 46).
My granny is 101, my mother is 79 (and travels to France every month to see her), my other granny lived till 96....so 45 in my family doesn't seem that old.
Though it does bother me sometimes, I wouldn't be without them and hope they'll be open minded enough to deal with having older parents....