I agree OP, I'm almost 34 and trying for our 3 and last. I always said I'd be done by 30 but a difficult DS and infertility has stopped that happening. Now I am so worried my chances are dropping by the day and I regret not trying earlier.
having said that, I wouldn't say anything to them. It's their life and their choice, and as others have said, everyone knows fertility drops at 35.