So if a married couple conceive a child when the father is 50 or even 60, what do you suggest? An abortion? Oh, but surely not—your tag line indicates that you agree with the rest of us that abortion is evil. Are you advocating that married people who are over a certain age abstain from sex forever?
If God didn’t want that little girl to exist, He wouldn’t have created her. It may not be wise to second-guess the Author of the Universe.
No, they don't have to abstain from sex. Do you need someone to tell you why they don't?